Release 8.0
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| Oracle Call Interface Programmer's Guide, Volumes 1 & 2 Release 8.0 A58234-01 |
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This chapter describes the Oracle8 OCI relational functions for C. It includes information about calling OCI functions in your application, along with detailed descriptions of each function call.
This chapter contains the following sections:
This chapter describes the OCI relational function calls. This chapter covers those functions in the basic OCI. The function calls for manipulating objects are described in the next three chapters.
For information about return codes and error handling, refer to the section "Error Handling" on page 2-25.
This table directs you to the location of a given OCI call in this chapter. The following list includes all OCI relational and type information accessor functions, grouped by functional category.
Unlike earlier versions of the OCI, in release 8.0 you cannot pass -1 for the string length parameter of a null-terminated string.
When you pass string lengths as parameters, do not include the NULL terminator byte in the length. The OCI does not expect strings to be NULL-terminated.
For a table showing the number of server roundtrips required for individual OCI LOB functions, refer to Appendix E, "OCI Function Server Roundtrips".
The remainder of this chapter specifies the release 8.0 OCI relational functions for C. For each function, the following information is listed:
A brief description of the action performed by the function.
A code snippet showing the syntax for calling the function, including the ordering and types of the parameters.
A description of each of the function's parameters. This includes the parameter's mode. The mode of a parameter has three possible values, as described below
More detailed information about the function (if available). This may include restrictions on the use of the function, or other information that might be useful when using the function in an application.
A complete or partial code example demonstrating the use of the function call being described. Not all function descriptions include an example.
A list of related function calls.
This call is used for an advanced queueing dequeue.
sword OCIAQDeq ( OCISvcCtx *svch, OCIError *errh, text *queue_name, OCIAQDeqOptions *dequeue_options, OCIAQMsgProperties *message_properties, OCIType *payload_tdo, dvoid **payload, dvoid **payload_ind, OCIRaw **msgid, ub4 flags );
OCI service context.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The target queue for the dequeue operation.
The options for the dequeue operation; stored in an OCIAQDeqOptions descriptor.
The message properties for the message; stored in an OCIAQMsgProperties descriptor.
The TDO (type descriptor object) of an object type. For a raw queue, this parameter should point to the TDO of SYS.RAW.
A pointer to a pointer to a program variable buffer that is an instance of an object type. For a raw queue, this parameter should point to an instance of OCIRaw.
Memory for the payload is dynamically allocated in the object cache. The application can optionally call OCIObjectFree() to deallocate the payload instance when it is no longer needed. If the pointer to the program variable buffer
( *payload) is passed as NULL, the buffer is implicitly allocated in the cache.
The application may choose to pass NULL for payload the first time OCIAQDeq() is called, and let the OCI allocate the memory for the payload. It can then use a pointer to that previously allocated memory in subsequent calls to OCIAQDeq().
The OCI provides functions which allow the user to set attributes of the payload, such as its text. For information about setting these attributes, refer to "Manipulating Object Attributes" on page 8-13.
A pointer to a pointer to the program variable buffer containing the parallel indicator structure for the object type.
The memory allocation rules for payload_ind are the same as those for payload, above.
The message ID.
Not currently used; pass as OCI_DEFAULT.
This function is used to perform an Advanced Queueing dequeue operation using the OCI.
Users must have the aq_user_role or privileges to execute the dbms_aq package in order to use this call.
The OCI environment must be initialized in object mode (using OCIInitialize()) to use this call.
For more information about OCI and Advanced Queueing, refer to "OCI and Advanced Queueing" on page 7-40.
For additional information about Advanced Queueing, refer to Oracle8 Application Developer's Guide.
To obtain a TDO for the payload, use OCITypeByName(), or OCITypeByRef().
For examples demonstrating the use of OCIAQDeq(), refer to the description of OCIAQEnq() on page 13-11.
This call is used for an advanced queueing enqueue.
sword OCIAQEnq ( OCISvcCtx *svch, OCIError *errh, text *queue_name, OCIAQEnqOptions *enqueue_options, OCIAQMsgProperties *message_properties, OCIType *payload_tdo, dvoid **payload, dvoid **payload_ind, OCIRaw **msgid, ub4 flags );
OCI service context.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The target queue for the enqueue operation.
The options for the enqueue operation; stored in an OCIAQEnqOptions descriptor.
The message properties for the message; stored in an OCIAQMsgProperties descriptor.
The TDO (type descriptor object) of an object type. For a raw queue, this parameter should point to the TDO of SYS.RAW.
A pointer to a pointer to an instance of an object type. For a raw queue, this parameter should point to an instance of OCIRaw.
The OCI provides functions which allow the user to set attributes of the payload, such as its text. For information about setting these attributes, refer to "Manipulating Object Attributes" on page 8-13.
A pointer to a pointer to the program variable buffer containing the parallel indicator structure for the object type.
The message ID.
Not currently used; pass as OCI_DEFAULT.
This function is used to perform an Advanced Queueing enqueue operation using the OCI.
Users must have the aq_user_role or privileges to execute the dbms_aq package in order to use this call.
The OCI environment must be initialized in object mode (using OCIInitialize()) to use this call.
For more information about OCI and Advanced Queueing, refer to "OCI and Advanced Queueing" on page 7-40.
For additional information about Advanced Queueing, refer to Oracle8 Application Developer's Guide.
To obtain a TDO for the payload, use OCITypeByName(), or OCITypeByRef().
The following four examples demonstrate the use of OCIAQEnq() and OCIAQDeq() in several different situations.
These examples assume that the database is set up as illustrated in the section "Oracle Advanced Queueing By Example" in the advanced queueing chapter of the Oracle8 Application Developer's Guide.
Enqueue and dequeue of a payload object.
struct message { OCIString *subject; OCIString *data; }; typedef struct message message; struct null_message { OCIInd null_adt; OCIInd null_subject; OCIInd null_data; }; typedef struct null_message null_message; int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; dvoid *tmp; OCIType *mesg_tdo = (OCIType *) 0; message msg; null_message nmsg; message *mesg = &msg; null_message *nmesg = &nmsg; message *deqmesg = (message *)0; null_message *ndeqmesg = (null_message *)0; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 52, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp); OCILogon(envhp, errhp, &svchp, "AQ", strlen("AQ"), "AQ", strlen("AQ"), 0, 0); /* obtain TDO of message_type */ OCITypeByName(envhp, errhp, svchp, (CONST text *)"AQ", strlen("AQ"), (CONST text *)"MESSAGE_TYPE", strlen("MESSAGE_TYPE"), (text *)0, 0, OCI_DURATION_SESSION, OCI_TYPEGET_ALL, &mesg_tdo); /* prepare the message payload */ mesg->subject = (OCIString *)0; mesg->data = (OCIString *)0; OCIStringAssignText(envhp, errhp, (CONST text *)"NORMAL MESSAGE", strlen("NORMAL MESSAGE"), &mesg->subject); OCIStringAssignText(envhp, errhp,(CONST text *)"OCI ENQUEUE", strlen("OCI ENQUEUE"), &mesg->data); nmesg->null_adt = nmesg->null_subject = nmesg->null_data = OCI_IND_NOTNULL; /* enqueue into the msg_queue */ OCIAQEnq(svchp, errhp, (CONST text *)"msg_queue", 0, 0, mesg_tdo, (dvoid **)&mesg, (dvoid **)&nmesg, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* dequeue from the msg_queue */ OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue", 0, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0); printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); OCITransCommit(svchp, errhp, (ub4) 0); }
Enqueue and dequeue using correlation IDs.
struct message { OCIString *subject; OCIString *data; }; typedef struct message message; struct null_message { OCIInd null_adt; OCIInd null_subject; OCIInd null_data; }; typedef struct null_message null_message; int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; dvoid *tmp; OCIType *mesg_tdo = (OCIType *) 0; message msg; null_message nmsg; message *mesg = &msg; null_message *nmesg = &nmsg; message *deqmesg = (message *)0; null_message *ndeqmesg = (null_message *)0; OCIRaw*firstmsg = (OCIRaw *)0; OCIAQMsgProperties *msgprop = (OCIAQMsgProperties *)0; OCIAQDeqOptions *deqopt = (OCIAQDeqOptions *)0; text correlation1[30], correlation2[30]; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 52, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp); OCILogon(envhp, errhp, &svchp, "AQ", strlen("AQ"), "AQ", strlen("AQ"), 0, 0); /* allocate message properties descriptor */ OCIDescriptorAlloc(envhp, (dvoid **)&msgprop, OCI_DTYPE_AQMSG_PROPERTIES, 0, (dvoid **)0); strcpy(correlation1, "1st message"); OCIAttrSet(msgprop, OCI_DTYPE_AQMSG_PROPERTIES, (dvoid *)&correlation1, strlen(correlation1), OCI_ATTR_CORRELATION, errhp); /* obtain TDO of message_type */ OCITypeByName(envhp, errhp, svchp, (CONST text *)"AQ", strlen("AQ"), (CONST text *)"MESSAGE_TYPE", strlen("MESSAGE_TYPE"), (text *)0, 0, OCI_DURATION_SESSION, OCI_TYPEGET_ALL, &mesg_tdo); /* prepare the message payload */ mesg->subject = (OCIString *)0; mesg->data = (OCIString *)0; OCIStringAssignText(envhp, errhp, (CONST text *)"NORMAL ENQUEUE1", strlen("NORMAL ENQUEUE1"), &mesg->subject); OCIStringAssignText(envhp, errhp,(CONST text *)"OCI ENQUEUE", strlen("OCI ENQUEUE"), &mesg->data); nmesg->null_adt = nmesg->null_subject = nmesg->null_data = OCI_IND_NOTNULL; /* enqueue into the msg_queue, store the message id into firstmsg */ OCIAQEnq(svchp, errhp, (CONST text *)"msg_queue", 0, msgprop, mesg_tdo, (dvoid **)&mesg, (dvoid **)&nmesg, &firstmsg, 0); /* enqueue into the msg_queue with a different correlation id */ strcpy(correlation2, "2nd message"); OCIAttrSet(msgprop, OCI_DTYPE_AQMSG_PROPERTIES, (dvoid*)&correlation2, strlen(correlation2), OCI_ATTR_CORRELATION, errhp); OCIStringAssignText(envhp, errhp, (CONST text *)"NORMAL ENQUEUE2", strlen("NORMAL ENQUEUE2"), &mesg->subject); OCIAQEnq(svchp, errhp, (CONST text *)"msg_queue", 0, msgprop, mesg_tdo, (dvoid **)&mesg, (dvoid **)&nmesg, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* first dequeue by correlation id "2nd message" */ /* allocate dequeue options descriptor and set the correlation option */ OCIDescriptorAlloc(envhp, (dvoid **)&deqopt, OCI_DTYPE_AQDEQ_OPTIONS, 0, (dvoid **)0); OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)correlation2,
strlen(correlation2), OCI_ATTR_CORRELATION, errhp); /* dequeue from the msg_queue */ OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue", deqopt, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0); printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); OCITransCommit(svchp, errhp, (ub4) 0); /* second dequeue by message id */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)&firstmsg, OCIRawSize(envhp, firstmsg), OCI_ATTR_DEQ_MSGID, errhp); /* clear correlation id option */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)correlation2, 0, OCI_ATTR_CORRELATION, errhp); /* dequeue from the msg_queue */ OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue", deqopt, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0); printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); OCITransCommit(svchp, errhp, (ub4) 0); }
Enqueue and dequeue of a raw queue.
int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; dvoid *tmp; OCIType *mesg_tdo = (OCIType *) 0; char msg_text[100]; OCIRaw *mesg = (OCIRaw *)0; OCIRaw*deqmesg = (OCIRaw *)0; OCIInd ind = 0; dvoid *indptr = (dvoid *)&ind; inti; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 52, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp); OCILogon(envhp, errhp, &svchp, "AQ", strlen("AQ"), "AQ", strlen("AQ"), 0, 0); /* obtain the TDO of the RAW data type */ OCITypeByName(envhp, errhp, svchp, (CONST text *)"SYS", strlen("SYS"), (CONST text *)"RAW", strlen("RAW"), (text *)0, 0, OCI_DURATION_SESSION, OCI_TYPEGET_ALL, &mesg_tdo); /* prepare the message payload */ strcpy(msg_text, "Enqueue to a RAW queue"); OCIRawAssignBytes(envhp, errhp, msg_text, strlen(msg_text), &mesg); /* enqueue the message into raw_msg_queue */ OCIAQEnq(svchp, errhp, (CONST text *)"raw_msg_queue", 0, 0, mesg_tdo, (dvoid **)&mesg, (dvoid **)&indptr, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* dequeue the same message into C variable deqmesg */ OCIAQDeq(svchp, errhp, (CONST text *)"raw_msg_queue", 0, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&indptr, 0, 0); for (i = 0; i < OCIRawSize(envhp, deqmesg); i++) printf("%c", *(OCIRawPtr(envhp, deqmesg) + i)); OCITransCommit(svchp, errhp, (ub4) 0); }
Enqueue and dequeue using OCIAQAgent.
struct message { OCIString *subject; OCIString *data; }; typedef struct message message; struct null_message { OCIInd null_adt; OCIInd null_subject; OCIInd null_data; }; typedef struct null_message null_message; int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; dvoid *tmp; OCIType *mesg_tdo = (OCIType *) 0; message msg; null_message nmsg; message *mesg = &msg; null_message *nmesg = &nmsg; message *deqmesg = (message *)0; null_message *ndeqmesg = (null_message *)0; OCIAQMsgProperties *msgprop = (OCIAQMsgProperties *)0; OCIAQAgent *agents[2]; OCIAQDeqOptions *deqopt = (OCIAQDeqOptions *)0; ub4wait = OCI_DEQ_NO_WAIT; ub4 navigation = OCI_DEQ_FIRST_MSG; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 52, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *)srvhp, (ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp); OCILogon(envhp, errhp, &svchp, "AQ", strlen("AQ"), "AQ", strlen("AQ"), 0, 0); /* obtain TDO of message_type */ OCITypeByName(envhp, errhp, svchp, (CONST text *)"AQ", strlen("AQ"), (CONST text *)"MESSAGE_TYPE", strlen("MESSAGE_TYPE"), (text *)0, 0, OCI_DURATION_SESSION, OCI_TYPEGET_ALL, &mesg_tdo); /* prepare the message payload */ mesg->subject = (OCIString *)0; mesg->data = (OCIString *)0; OCIStringAssignText(envhp, errhp, (CONST text *)"MESSAGE 1", strlen("MESSAGE 1"), &mesg->subject); OCIStringAssignText(envhp, errhp, (CONST text *)"mesg for queue subscribers", strlen("mesg for queue subscribers"), &mesg->data); nmesg->null_adt = nmesg->null_subject = nmesg->null_data = OCI_IND_NOTNULL; /* enqueue MESSAGE 1 for subscribers to the queue i.e. for RED and GREEN */ OCIAQEnq(svchp, errhp, (CONST text *)"msg_queue_multiple", 0, 0, mesg_tdo, (dvoid **)&mesg, (dvoid **)&nmesg, 0, 0); /* enqueue MESSAGE 2 for specified recipients i.e. for RED and BLUE */ /* prepare message payload */ OCIStringAssignText(envhp, errhp, (CONST text *)"MESSAGE 2", strlen("MESSAGE 2"), &mesg->subject); OCIStringAssignText(envhp, errhp, (CONST text *)"mesg for two recipients", strlen("mesg for two recipients"), &mesg->data); /* allocate AQ message properties and agent descriptors */ OCIDescriptorAlloc(envhp, (dvoid **)&msgprop, OCI_DTYPE_AQMSG_PROPERTIES, 0, (dvoid **)0); OCIDescriptorAlloc(envhp, (dvoid **)&agents[0], OCI_DTYPE_AQAGENT, 0, (dvoid **)0); OCIDescriptorAlloc(envhp, (dvoid **)&agents[1], OCI_DTYPE_AQAGENT, 0, (dvoid **)0); /* prepare the recipient list, RED and BLUE */ OCIAttrSet(agents[0], OCI_DTYPE_AQAGENT, "RED", strlen("RED"), OCI_ATTR_AGENT_NAME, errhp); OCIAttrSet(agents[1], OCI_DTYPE_AQAGENT, "BLUE", strlen("BLUE"), OCI_ATTR_AGENT_NAME, errhp); OCIAttrSet(msgprop, OCI_DTYPE_AQMSG_PROPERTIES, (dvoid *)agents, 2, OCI_ATTR_RECIPIENT_LIST, errhp); OCIAQEnq(svchp, errhp, (CONST text *)"msg_queue_multiple", 0, msgprop, mesg_tdo, (dvoid **)&mesg, (dvoid **)&nmesg, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* now dequeue the messages using different consumer names */ /* allocate dequeue options descriptor to set the dequeue options */ OCIDescriptorAlloc(envhp, (dvoid **)&deqopt, OCI_DTYPE_AQDEQ_OPTIONS, 0, (dvoid **)0); /* set wait parameter to NO_WAIT so that the dequeue returns immediately */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)&wait, 0, OCI_ATTR_WAIT, errhp); /* set navigation to FIRST_MESSAGE so that the dequeue resets the position */ /* after a new consumer_name is set in the dequeue options */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)&navigation, 0, OCI_ATTR_NAVIGATION, errhp); /* dequeue from the msg_queue_multiple as consumer BLUE */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)"BLUE", strlen("BLUE"), OCI_ATTR_CONSUMER_NAME, errhp); while (OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue_multiple", deqopt, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0) == OCI_SUCCESS) { printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); } OCITransCommit(svchp, errhp, (ub4) 0); /* dequeue from the msg_queue_multiple as consumer RED */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS, (dvoid *)"RED", strlen("RED"), OCI_ATTR_CONSUMER_NAME, errhp); while (OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue_multiple", deqopt, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0) == OCI_SUCCESS) { printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); } OCITransCommit(svchp, errhp, (ub4) 0); /* dequeue from the msg_queue_multiple as consumer GREEN */ OCIAttrSet(deqopt, OCI_DTYPE_AQDEQ_OPTIONS,(dvoid *)"GREEN",strlen("GREEN"), OCI_ATTR_CONSUMER_NAME, errhp); while (OCIAQDeq(svchp, errhp, (CONST text *)"msg_queue_multiple", deqopt, 0, mesg_tdo, (dvoid **)&deqmesg, (dvoid **)&ndeqmesg, 0, 0) == OCI_SUCCESS) { printf("Subject: %s\n", OCIStringPtr(envhp, deqmesg->subject)); printf("Text: %s\n", OCIStringPtr(envhp, deqmesg->data)); } OCITransCommit(svchp, errhp, (ub4) 0); }
This call is used to get a particular attribute of a handle.
sword OCIAttrGet ( CONST dvoid *trgthndlp, ub4 trghndltyp, dvoid *attributep, ub4 *sizep, ub4 attrtype, OCIError *errhp );
Pointer to a handle type.
The handle type.
Pointer to the storage for an attribute value. The attribute value is filled in.
The size of storage for the attribute value. This can be passed in as NULL for parameters whose size is well known. For text* parameters, a pointer to a ub4 must be passed in to get the length of the string.
The type of attribute being retrieved.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
This call is used to get a particular attribute of a handle.
See Appendix B, "Handle and Descriptor Attributes", for a list of handle types and their readable attributes.
This call is used to set a particular attribute of a handle or a descriptor.
sword OCIAttrSet ( dvoid *trgthndlp, ub4 trghndltyp, dvoid *attributep, ub4 size, ub4 attrtype, OCIError *errhp );
Pointer to a handle type whose attribute gets modified.
The handle type.
Pointer to an attribute value. The attribute value is copied into the target handle. If the attribute value is a pointer, then only the pointer is copied, not the contents of the pointer.
The size of an attribute value. This can be passed in as 0 for most attributes as the size is already known by the OCI library. For text* attributes, a ub4 must be passed in set to the length of the string.
The type of attribute being set.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
This call is used to set a particular attribute of a handle or a descriptor.
See Appendix B, "Handle and Descriptor Attributes", for a list of handle types and their writable attributes.
The following code sample demonstrates OCIAttrSet() being used several times near the beginning of an application.
int main()
{
OCIEnv *envhp;
OCIServer *srvhp;
OCIError *errhp;
OCISvcCtx *svchp;
OCIStmt *stmthp;
OCISession *usrhp; OCIInitialize((ub4) OCI_THREADED | OCI_OBJECT, (dvoid *)0,
(dvoid * (*)()) 0,(dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV,
0, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 0, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4)
OCI_HTYPE_ERROR, 0, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4)
OCI_HTYPE_SERVER, 0, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp,
(ub4) OCI_HTYPE_SVCCTX, , (dvoid **) &tmp); /* set attribute server context in the service context */ OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *) srvhp,
(ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp); /* allocate a user session handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&usrhp,
(ub4) OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"sherry",
(ub4)strlen("sherry"), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"penfield",
(ub4)strlen("penfield"), OCI_ATTR_PASSWORD, errhp); checkerr(errhp, OCISessionBegin (svchp, errhp, usrhp, OCI_CRED_RDBMS,
OCI_DEFAULT)); OCIAttrSet((dvoid *)svchp, (ub4)OCI_HTYPE_SVCCTX, (dvoid *)usrhp,
(ub4)0, OCI_ATTR_SESSION, errhp);
This call sets up the skip parameters for a static array bind.
sword OCIBindArrayOfStruct ( OCIBind *bindp, OCIError *errhp, ub4 pvskip, ub4 indskip, ub4 alskip, ub4 rcskip );
The handle to a bind structure.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Skip parameter for the next data value.
Skip parameter for the next indicator value or structure.
Skip parameter for the next actual length value.
Skip parameter for the next column-level return code value.
This call sets up the skip parameters necessary for a static array bind.
This call follows a call to OCIBindByName() or OCIBindByPos(). The bind handle returned by that initial bind call is used as a parameter for the OCIBindArrayOfStruct() call.
For information about skip parameters, see the section "Arrays of Structures" on page 5-17.
OCIBindByName(), OCIBindByPos()
Creates an association between a program variable and a placeholder in a SQL statement or PL/SQL block.
sword OCIBindByName ( OCIStmt *stmtp, OCIBind **bindpp, OCIError *errhp, CONST text *placeholder, sb4 placeh_len, dvoid *valuep, sb4 value_sz, ub2 dty, dvoid *indp, ub2 *alenp, ub2 *rcodep, ub4 maxarr_len, ub4 *curelep, ub4 mode );
The statement handle to the SQL or PL/SQL statement being processed.
An address of a bind handle which is implicitly allocated by this call. The bind handle maintains all the bind information for this particular input value. The handle is freed implicitly when the statement handle is deallocated. On input, the value of the pointer must be NULL or a valid bind handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The placeholder attributes are specified by name if OCIBindByName() is being called.
The length of the placeholder name specified in placeholder.
An address of a data value or an array of data values of the type specified in the dty parameter. An array of data values can be specified for mapping into a PL/SQL table or for providing data for SQL multiple-row operations. When an array of bind values is provided, this is called an array bind in OCI terms.
For SQLT_NTY or SQLT_REF binds, the valuep parameter is ignored. The pointers to OUT buffers are set in the pgvpp parameter initialized by OCIBindObject().
The size of a data value. In the case of an array bind, this is the maximum size of any element possible with the actual sizes being specified in the alenp parameter.
For descriptors, locators, or REFs, whose size is unknown to client applications use the size of the structure you are passing in; e.g., sizeof (OCILobLocator *).
The data type of the value(s) being bound. Named data types (SQLT_NTY) and REFs (SQLT_REF) are valid only if the application has been initialized in object mode. For named data types, or REFs, additional calls must be made with the bind handle to set up the datatype-specific attributes.
Pointer to an indicator variable or array. For all data types except SQLT_NTY, this is a pointer to sb2 or an array of sb2s.
For SQLT_NTY, this pointer is ignored and the actual pointer to the indicator structure or an array of indicator structures is initialized in a subsequent call OCIBindObject(). This parameter is ignored for dynamic binds.
See the section "Indicator Variables" on page 2-29 for more information about indicator variables.
Pointer to array of actual lengths of array elements. Each element in alenp is the length of the data in the corresponding element in the bind value array before and after the execute. This parameter is ignored for dynamic binds.
Pointer to array of column level return codes. This parameter is ignored for dynamic binds.
The maximum possible number of elements of type dty in a PL/SQL binds. This parameter is not required for non-PL/SQL binds. If maxarr_len is non-zero, then either OCIBindDynamic() or OCIBindArrayOfStruct() can be invoked to set up additional bind attributes.
A pointer to the actual number of elements. This parameter is only required for
PL/SQL binds.
The valid modes for this parameter are:
OCI_DEFAULT - This is default mode.
OCI_DATA_AT_EXEC - When this mode is selected, the value_sz parameter defines the maximum size of the data that can be ever provided at runtime. The application must be ready to provide the OCI library runtime IN data buffers at any time and any number of times. Runtime data is provided in one of the two ways:
For more information about using the OCI_DATA_AT_EXEC mode, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
When the allocated buffers are not required any more, they should be freed by the client.
This call is used to perform a basic bind operation. The bind creates an association between the address of a program variable and a placeholder in a SQL statement or PL/SQL block. The bind call also specifies the type of data which is being bound, and may also indicate the method by which data will be provided at runtime.
This function also implicitly allocates the bind handle indicated by the bindpp parameter. If a non-NULL pointer is passed in **bindpp, the OCI assumes that this points to a valid handle that has been previously allocated with a call to OCIHandleAlloc() or OCIBindByName().
Data in an OCI application can be bound to placeholders statically or dynamically. Binding is static when all the IN bind data and the OUT bind buffers are well-defined just before the execute. Binding is dynamic when the IN bind data and the OUT bind buffers are provided by the application on demand at execute time to the client library. Dynamic binding is indicated by setting the mode parameter of this call to OCI_DATA_AT_EXEC.
See Also: For more information about dynamic binding, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
Both OCIBindByName() and OCIBindByPos() take as a parameter a bind handle, which is implicitly allocated by the bind call A separate bind handle is allocated for each placeholder the application is binding.
Additional bind calls may be required to specify particular attributes necessary when binding certain data types or handling input data in certain ways:
OCIBindDynamic(), OCIBindObject(), OCIBindArrayOfStruct()
Creates an association between a program variable and a placeholder in a SQL statement or PL/SQL block.
sword OCIBindByPos ( OCIStmt *stmtp, OCIBind **bindpp, OCIError *errhp, ub4 position, dvoid *valuep, sb4 value_sz, ub2 dty, dvoid *indp, ub2 *alenp, ub2 *rcodep, ub4 maxarr_len, ub4 *curelep, ub4 mode );
The statement handle to the SQL or PL/SQL statement being processed.
An address of a bind handle which is implicitly allocated by this call. The bind handle maintains all the bind information for this particular input value. The handle is freed implicitly when the statement handle is deallocated. On input, the value of the pointer must be NULL or a valid bind handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The placeholder attributes are specified by position if OCIBindByPos() is being called.
An address of a data value or an array of data values of the type specified in the dty parameter. An array of data values can be specified for mapping into a PL/SQL table or for providing data for SQL multiple-row operations. When an array of bind values is provided, this is called an array bind in OCI terms.
For SQLT_NTY or SQLT_REF binds, the valuep parameter is ignored. The pointers to OUT buffers are set in the pgvpp parameter initialized by OCIBindObject().
The size of a data value. In the case of an array bind, this is the maximum size of any element possible with the actual sizes being specified in the alenp parameter.
For descriptors, locators, or REFs, whose size is unknown to client applications use the size of the structure you are passing in; e.g., sizeof (OCILobLocator *).
The data type of the value(s) being bound. Named data types (SQLT_NTY) and REFs (SQLT_REF) are valid only if the application has been initialized in object mode. For named data types, or REFs, additional calls must be made with the bind handle to set up the datatype-specific attributes.
Pointer to an indicator variable or array. For all data types, this is a pointer to sb2 or an array of sb2s. The only exception is SQLT_NTY, when this pointer is ignored and the actual pointer to the indicator structure or an array of indicator structures is initialized by OCIBindObject(). Ignored for dynamic binds.
See the section "Indicator Variables" on page 2-29 for more information about indicator variables.
Pointer to array of actual lengths of array elements. Each element in alenp is the length of the data in the corresponding element in the bind value array before and after the execute. This parameter is ignored for dynamic binds.
Pointer to array of column level return codes. This parameter is ignored for dynamic binds.
The maximum possible number of elements of type dty in a PL/SQL binds. This parameter is not required for non-PL/SQL binds. If maxarr_len is non-zero, then either OCIBindDynamic() or OCIBindArrayOfStruct() can be invoked to set up additional bind attributes.
A pointer to the actual number of elements. This parameter is only required for
PL/SQL binds.
The valid modes for this parameter are:
OCI_DEFAULT - This is default mode.
OCI_DATA_AT_EXEC - When this mode is selected, the value_sz parameter defines the maximum size of the data that can be ever provided at runtime. The application must be ready to provide the OCI library runtime IN data buffers at any time and any number of times. Runtime data is provided in one of the two ways:
For more information about using the OCI_DATA_AT_EXEC mode, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
When the allocated buffers are not required any more, they should be freed by the client.
This call is used to perform a basic bind operation. The bind creates an association between the address of a program variable and a placeholder in a SQL statement or PL/SQL block. The bind call also specifies the type of data which is being bound, and may also indicate the method by which data will be provided at runtime.
This function also implicitly allocates the bind handle indicated by the bindpp parameter. If a non-NULL pointer is passed in **bindpp, the OCI assumes that this points to a valid handle that has been previously allocated with a call to OCIHandleAlloc() or OCIBindByPos().
Data in an OCI application can be bound to placeholders statically or dynamically. Binding is static when all the IN bind data and the OUT bind buffers are well-defined just before the execute. Binding is dynamic when the IN bind data and the OUT bind buffers are provided by the application on demand at execute time to the client library. Dynamic binding is indicated by setting the mode parameter of this call to OCI_DATA_AT_EXEC.
See Also: For more information about dynamic binding, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16
Both OCIBindByName() and OCIBindByPos() take as a parameter a bind handle, which is implicitly allocated by the bind call A separate bind handle is allocated for each placeholder the application is binding.
Additional bind calls may be required to specify particular attributes necessary when binding certain data types or handling input data in certain ways:
OCIBindDynamic(), OCIBindObject(), OCIBindArrayOfStruct()
This call is used to register user callbacks for dynamic data allocation.
sword OCIBindDynamic ( OCIBind *bindp, OCIError *errhp, dvoid *ictxp, OCICallbackInBind (icbfp)(/*_ dvoid *ictxp, OCIBind *bindp, ub4 iter, ub4 index, dvoid **bufpp, ub4 *alenp, ub1 *piecep, dvoid **indpp */), dvoid *octxp, OCICallbackOutBind (ocbfp)(/*_ dvoid *octxp, OCIBind *bindp, ub4 iter, ub4 index, dvoid **bufpp, ub4 **alenpp, ub1 *piecep, dvoid **indpp, ub2 **rcodepp _*/) );
A bind handle returned by a call to OCIBindByName() or OCIBindByPos().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The context pointer required by the call back function icbfp.
The callback function which returns a pointer to the IN bind value or piece at run time. The callback takes in the following parameters:
The context pointer for this callback function.
bindp (IN)The bind handle passed in to uniquely identify this bind variable.
iter (IN)0-based execute iteration value.
index (IN)Index of the current array, for an array bind in PL/SQL. For SQL it is the row index. The value is 0-based and not greater than curelep parameter of the bind call.
bufpp (OUT)The pointer to the buffer or storage. For descriptors, *bufpp contains a pointer to the descriptor. For example if you define
OCILOBLocator *lobp;
then you would set *bufpp to lobp not *lobp.
For REFs, pass the address of the ref; i.e., pass &my_ref for *bufpp.
A pointer to a storage for OCI to fill in the size of the bind
value/piece after it has been read. For descriptors, pass the size of the pointer to the descriptor; e.g., sizeof(OCILobLocator *).
Which piece of the bind value. This can be one of the following values OCI_ONE_PIECE, OCI_FIRST_PIECE, OCI_NEXT_PIECE and OCI_LAST_PIECE. For datatypes that do not support piecewise operations, you must pass OCI_ONE_PIECE or an error will be generated.
indp (OUT)Contains the indicator value. This is a pointer to either an sb2 value or a pointer to an indicator structure for binding named data types.
octxp (IN)The context pointer required by the callback function ocbfp.
The callback function which returns a pointer to the OUT bind value or piece at run time. The callback takes in the following parameters:
The context pointer for this call back function.
bindp (IN)The bind handle passed in to uniquely identify this bind variable.
iter (IN)0-based execute iteration value.
index (IN)For PL/SQL index of the current array, for an array bind. For SQL, the index is the row number in the current iteration. It is 0-based, and must not be greater than curelep parameter of the bind call.
bufpp (OUT)A pointer to a buffer to write the bind value/piece.
alenpp (IN/OUT)A pointer to a storage for OCI to fill in the size of the bind value/piece after it has been read.
piecep (IN/OUT)Returns a piece value from the callback (application) to Oracle, as follows:
indpp (OUT)Returns a pointer to contain the indicator value which either an sb2 value or a pointer to an indicator structure for named data types.
rcodepp (OUT)Returns a pointer to contains the return code.
This call is used to register user-defined callback functions for providing or receiving data if OCI_DATA_AT_EXEC mode was specified in a previous call to OCIBindByName() or OCIBindByPos().
The callback function pointers must return OCI_CONTINUE if it the call is successful. Any return code other than OCI_CONTINUE signals that the client wishes to abort processing immediately.
For more information about the OCI_DATA_AT_EXEC mode, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
When passing the address of a storage area, make sure that the storage area will exist even after the application returns from the callback. This means that you should not allocate such storage on the stack.
OCIBindByName(), OCIBindByPos()
This function sets up additional attributes which are required for a named data type (object) bind.
sword OCIBindObject ( OCIBind *bindp, OCIError *errhp, CONST OCIType *type, dvoid **pgvpp, ub4 *pvszsp, dvoid **indpp, ub4 *indszp, );
The bind handle returned by the call to OCIBindByName() or OCIBindByPos().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Points to the TDO which describes the type of the program variable being bound. Retrieved by calling OCITypeByName(). Optional for REFs in SQL, but required for REFs in PL/SQL.
Address of the program variable buffer. For an array, pgvpp points to an array of addresses. When the bind variable is also an OUT variable, the OUT Named Data Type value or REF is allocated in the Object Cache, and a REF is returned.
pgvpp is ignored if the OCI_DATA_AT_EXEC mode is set. Then the Named Data Type buffers are requested at runtime. For static array binds, skip factors may be specified using the OCIBindArrayOfStruct() call. The skip factors are used to compute the address of the next pointer to the value, the indicator structure and their sizes.
Points to the size of the program variable. The size of the named data type is not required on input. For an array, pvszsp is an array of ub4s. On return, for OUT bind variables, this points to size(s) of the Named Data Types and REFs received. pvszsp is ignored if the OCI_DATA_AT_EXEC mode is set. Then the size of the buffer is taken at runtime.
Address of the program variable buffer containing the parallel indicator structure. For an array, points to an array of pointers. When the bind variable is also an OUT bind variable, memory is allocated in the object cache, to store the OUT indicator values. At the end of the execute when all OUT values have been received, indpp points to the pointer(s) to these newly allocated indicator structure(s). Required only for SQLT_NTY binds.
indpp is ignored if the OCI_DATA_AT_EXEC mode is set. Then the indicator is requested at runtime.
Points to the size of the IN indicator structure program variable. For an array, it is an array of sb2s. On return for OUT bind variables, this points to size(s) of the received OUT indicator structures.
indszp is ignored if the OCI_DATA_AT_EXEC mode is set. Then the indicator size is requested at runtime.
This function sets up additional attributes which binding a named data type or a REF. An error will be returned if this function is called when the OCI environment has been initialized in non-object mode.
This call takes as a parameter a type descriptor object (TDO) of datatype OCIType for the named data type being defined. The TDO can be retrieved with a call to OCITypeByName().
If the OCI_DATA_AT_EXEC mode was specified in OCIBindByName() or OCIBindByPos(), the pointers to the IN buffers are obtained either using the callback icbfp registered in the OCIBindDynamic() call or by the OCIStmtSetPieceInfo() call. The buffers are dynamically allocated for the OUT data and the pointers to these buffers are returned either by calling ocbfp() registered by the OCIBindDynamic() or by setting the pointer to the buffer in the buffer passed in by OCIStmtSetPieceInfo() called when OCIStmtExecute() returned OCI_NEED_DATA. The memory of these client library-allocated buffers must be freed when not in use anymore by using the OCIObjectFree() call.
OCIBindByName(), OCIBindByPos()
This call performs an immediate (asynchronous) abort of any currently executing OCI function that is associated with a server.
sword OCIBreak ( dvoid *hndlp, OCIError *errhp);
The service context handle or the server context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
This call performs an immediate (asynchronous) abort of any currently executing OCI function that is associated with a server. It is normally used to stop a long-running OCI call being processed on the server.
This call can take either the service context handle or the server context handle as a parameter to identify the function to be aborted.
This call specifies additional attributes necessary for a static array define.
sword OCIDefineArrayOfStruct ( OCIDefine *defnp, OCIError *errhp, ub4 pvskip, ub4 indskip, ub4 rlskip, ub4 rcskip );
The handle to the define structure which was returned by a call to OCIDefineByPos().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Skip parameter for the next data value.
Skip parameter for the next indicator location.
Skip parameter for the next return length value.
Skip parameter for the next return code.
This call specifies additional attributes necessary for an array define, used in an array of structures (multi-row, multi-column) fetch. This call follows a call to OCIDefineByPos().
For more information about skip parameters, see the section "Skip Parameters" on page 5-18.
If the application is binding an array of structures involving objects, it must call OCIDefineObject() first, and then call OCIDefineArrayOfStruct().
OCIDefineByPos(), OCIDefineObject()
Associates an item in a select-list with the type and output data buffer.
sword OCIDefineByPos ( OCIStmt *stmtp, OCIDefine **defnpp, OCIError *errhp, ub4 position, dvoid *valuep, sb4 value_sz, ub2 dty, dvoid *indp, ub2 *rlenp, ub2 *rcodep, ub4 mode );
A handle to the requested SQL query operation.
A pointer to a pointer to a define handle. If this parameter is passed as NULL, this call implicitly allocates the define handle. In the case of a redefine, a non-NULL handle can be passed in this parameter. This handle is used to store the define information for this column.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The position of this value in the select list. Positions are 1-based and are numbered from left to right. For example, in the SELECT statement
SELECT empno, ssn, mgrno FROM employees;
empno is at position 1, ssn is at position 2, and mgrno is at position 3.
A pointer to a buffer or an array of buffers of the type specified in the dty parameter. A number of buffers can be specified when results for more than one row are desired in a single fetch call.
The size of each valuep buffer in bytes. If the data is stored internally in VARCHAR2 format, the number of characters desired, if different from the buffer size in bytes, may be additionally specified by the using OCIAttrSet().
In an NLS conversion environment, a truncation error will be generated if the number of bytes specified is insufficient to handle the number of characters desired.
The data type. Named data type (SQLT_NTY) and REF (SQLT_REF) are valid only if the environment has been initialized with in object mode. For a listing of datatype codes and values, refer to Chapter 3, "Datatypes".
pointer to an indicator variable or array. For scalar data types, pointer to sb2 or an array of sb2s. Ignored for SQLT_NTY defines. For SQLT_NTY defines, a pointer to a named data type indicator structure or an array of named data type indicator structures is associated by a subsequent OCIDefineObject() call.
See the section "Indicator Variables" on page 2-29 for more information about indicator variables.
Pointer to array of length of data fetched. Each element in rlenp is the length of the data in the corresponding element in the row after the fetch.
Pointer to array of column-level return codes
The valid modes are:
This call defines an output buffer which will receive data retrieved from Oracle. The define is a local step which is necessary when a SELECT statement returns data to your OCI application.
This call also implicitly allocates the define handle for the select-list item. If a non-NULL pointer is passed in *defnpp, the OCI assumes that this points to a valid handle that has been previously allocated with a call to OCIHandleAlloc() or OCIDefineByPos(). This would be true in the case of an application which is redefining a handle to a different addresses so it can reuse the same define handle for multiple fetches.
Defining attributes of a column for a fetch is done in one or more calls. The first call is to OCIDefineByPos(), which defines the minimal attributes required to specify the fetch.
Following the call to OCIDefineByPos() additional define calls may be necessary for certain data types or fetch modes:
For a LOB define, the buffer pointer must be a pointer to a lob locator of type OCILobLocator, allocated by the OCIDescriptorAlloc() call. LOB locators, and not LOB values, are always returned for a LOB column. LOB values can then be fetched using OCI LOB calls on the fetched locator. This same mechanism is true for all descriptor datatypes.
For NCHAR (fixed and varying length), the buffer pointer must point to an array of bytes sufficient for holding the required NCHAR characters.
Nested table columns are defined and fetched like any other named data type.
When defining an array of descriptors or locators, you should pass in an array of pointers to descriptors or locators.
When doing an array define for character columns, you should pass in an array of character buffers.
If the mode parameter is this call is set to OCI_DYNAMIC_FETCH, the client application can fetch data dynamically at runtime. Runtime data can be provided in one of two ways:
See Also: For more information about using the OCI_DYNAMIC_FETCH mode, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
For more information about defines, see "Defining" on page 5-13.
OCIDefineArrayOfStruct(), OCIDefineDynamic(), OCIDefineObject()
This call is used to set the additional attributes required if the OCI_DYNAMIC_FETCH mode was selected in OCIDefineByPos().
sword OCIDefineDynamic ( OCIDefine *defnp, OCIError *errhp, dvoid *octxp, OCICallbackDefine (ocbfp)(/*_ dvoid *octxp, OCIDefine *defnp, ub4 iter, dvoid **bufpp, ub4 **alenpp, ub1 *piecep, dvoid **indpp, ub2 **rcodep _*/) );
The handle to a define structure returned by a call to OCIDefineByPos().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Points to a context for the callback function.
Points to a callback function. This is invoked at runtime to get a pointer to the buffer into which the fetched data or a piece of it will be retrieved. The callback also specifies the indicator, the return code and the lengths of the data piece and indicator.
Warning: When working with callback parameters, it is important to keep in mind what is meant by IN and OUT for the parameter mode. Normally, in an OCI function, an IN parameter refers to data being passed to Oracle, and an OUT parameter refers to data coming back from Oracle. In the case of callbacks, this is reversed. IN means data is coming from Oracle into the callback, and OUT means data is coming out of the callback and going to Oracle.
The callback parameters are listed below:
A context pointer passed as an argument to all the callback functions.
defnp (IN)The define handle.
iter (IN)Which row of this current fetch; 0-based.
bufpp (OUT)Returns to Oracle a pointer to a buffer to store the column value, i.e., *bufpp points to some appropriate storage for the column value.
alenpp (IN/OUT)Used by the application to set the size of the storage it is providing in *bufpp. After data is fetched into the buffer, alenpp indicates the actual size of the data.
piecep (IN/OUT)Returns a piece value from the callback (application) to Oracle, as follows:
indpp (IN)Indicator variable pointer
rcodep (IN)Return code variable pointer
This call is used to set the additional attributes required if the OCI_DYNAMIC_FETCH mode has been selected in a call to OCIDefineByPos().
If OCI_DYNAMIC_FETCH mode was selected, and the call to OCIDefineDynamic() is skipped, then the application can fetch data piecewise using OCI calls (OCIStmtGetPieceInfo() and OCIStmtSetPieceInfo()).
For more information about OCI_DYNAMIC_FETCH mode, see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
Sets up additional attributes necessary for a Named Data Type or REF define.
sword OCIDefineObject ( OCIDefine *defnp, OCIError *errhp, CONST OCIType *type, dvoid **pgvpp, ub4 *pvszsp, dvoid **indpp, ub4 *indszp );
A define handle previously allocated in a call to OCIDefineByPos().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Points to the Type Descriptor Object (TDO) which describes the type of the program variable. Only used for program variables of type SQLT_NTY. This parameter is optional, and may be passed as NULL if it is not being used.
Points to a pointer to a program variable buffer. For an array, pgvpp points to an array of pointers. Memory for the fetched named data type instance(s) is dynamically allocated in the object cache. At the end of the fetch when all the values have been received, pgvpp points to the pointer(s) to these newly allocated named data type instance(s). The application must call OCIObjectFree() to deallocate the named data type instance(s) when they are no longer needed.
Note: If the application wants the buffer to be implicitly allocated in the cache, *pgvpp should be passed in as NULL.
pvszsp (IN/OUT)Points to the size of the program variable. For an array, it is an array of ub4s.
Points to a pointer to the program variable buffer containing the parallel indicator structure. For an array, points to an array of pointers. Memory is allocated to store the indicator structures in the object cache. At the end of the fetch when all values have been received, indpp points to the pointer(s) to these newly allocated indicator structure(s).
Points to the size(s) of the indicator structure program variable. For an array, it is an array of ub4s.
This function follows a call to OCIDefineByPos() to set initial define information. This call sets up additional attributes necessary for a Named Data Type define. An error will be returned if this function is called when the OCI environment has been initialized in non-Object mode.
This call takes as a parameter a type descriptor object (TDO) of datatype OCIType for the named data type being defined. The TDO can be retrieved with a call to OCIDescribeAny().
See Also: See the description of OCIInitialize() on page 13 - 72 for more information about initializing the OCI process environment.
Describes existing schema objects.
sword OCIDescribeAny ( OCISvcCtx *svchp, OCIError *errhp, dvoid *objptr, ub4 objnm_len, ub1 objptr_typ, ub1 info_level, ub1 objtyp, OCIDescribe *dschp );
A service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
This parameter can be either
These cases are distinguished by passing the appropriate value for objptr_typ. This parameter must be non-NULL.
In case 1, the string containing the object name should be in the format <schema-name>.<object-name>. No database links are allowed.
The object name is interpreted by the following SQL rules:
The length of the name string pointed to by objptr. Must be non-zero if a name is passed. Can be zero if objptr is a pointer to a TDO or its REF.
The type of object passed in objptr. Valid values are:
Reserved for future extensions. Pass OCI_DEFAULT.
The type of schema object being described. Valid values are:
A value for this argument must be specified. If OCI_PTYPE_UNK is specified, then the description of an object with the specified name in the current schema is returned, if such an object exists, along with the actual type of the object.
A describe handle that is populated with describe information about the object after the call. Must be non-NULL.
This is a generic describe call that describes existing schema objects: tables, views, synonyms, procedures, functions, packages, sequences, and types. This call populates the describe handle with the object-specific attributes which can be obtained through an OCIAttrGet() call.
An OCIParamGet() on the describe handle returns a parameter descriptor for a specified position. Parameter positions begin with 1. Calling OCIAttrGet() on the parameter descriptor returns the specific attributes of a stored procedure or function parameter or a table column descriptor as the case may be.
These subsequent calls do not need an extra round trip to the server because the entire schema object description cached on the client side by OCIDescribeAny(). Calling OCIAttrGet() on the describe handle can also return the total number of positions.
See Chapter 6, "Describing Schema Metadata", for more information about describe operations.
Allocates storage to hold descriptors or LOB locators.
sword OCIDescriptorAlloc ( CONST dvoid *parenth, dvoid **descpp, ub4 type, size_t xtramem_sz, dvoid **usrmempp);
An environment handle.
Returns a descriptor or LOB locator of desired type.
Specifies the type of descriptor or LOB locator to be allocated:
Specifies an amount of user memory to be allocated for use by the application for the lifetime of the descriptor.
Returns a pointer to the user memory of size xtramem_sz allocated by the call for the user for the lifetime of the descriptor.
Returns a pointer to an allocated and initialized descriptor, corresponding to the type specified in type. A non-NULL descriptor or LOB locator is returned on success. No diagnostics are available on error.
This call returns OCI_SUCCESS if successful, or OCI_INVALID_HANDLE if an out-of-memory error occurs.
For more information about the xtramem_sz parameter and user memory allocation, refer to "User Memory Allocation" on page 2-12.
Deallocates a previously allocated descriptor.
sword OCIDescriptorFree ( dvoid *descp, ub4 type );
An allocated descriptor.
Specifies the type of storage to be freed. The specific types are:
This call frees storage associated with a descriptor. Returns OCI_SUCCESS or OCI_INVALID_HANDLE. All descriptors may be explicitly deallocated, however the OCI will deallocate a descriptor if the environment handle is deallocated.
This call allocates and initializes an OCI environment handle.
sword OCIEnvInit ( OCIEnv **envhpp, ub4 mode, size_t xtramemsz, dvoid **usrmempp );
A pointer to a handle to the environment.
Specifies initialization of an environment mode. Valid modes are:
In OCI_DEFAULT mode, the OCI library always mutexes handles. In OCI_NO_MUTEX modes, there is no mutexing in this environment.
Specifies the amount of user memory to be allocated for the duration of the environment.
Returns a pointer to the user memory of size xtramemsz allocated by the call for the user for the duration of the environment.
This call allocates and initializes an OCI environment handle. No changes are done to an already initialized handle. If OCI_ERROR or OCI_SUCCESS_WITH_INFO is returned, the environment handle can be used to obtain ORACLE specific errors and diagnostics.
This call is processed locally, without a server round-trip.
The environment handle can be freed using OCIHandleFree().
For more information about the xtramemsz parameter and user memory allocation, refer to "User Memory Allocation" on page 2-12.
OCIHandleAlloc(), OCIHandleFree()
Returns an error message in the buffer provided and an ORACLE error.
sword OCIErrorGet ( dvoid *hndlp, ub4 recordno, text *sqlstate, sb4 *errcodep, text *bufp, ub4 bufsiz, ub4 type );
The error handle, in most cases, or the environment handle (for errors on OCIEnvInit(), OCIHandleAlloc()).
Indicates the status record from which the application seeks info. Starts from 1.
Not supported in Version 8.0.
An ORACLE Error is returned.
The error message text is returned.
The size of the buffer provide to get the error message.
The type of the handle (OCI_HTYPE_ERR or OCI_HTYPE_ENV).
Returns an error message in the buffer provided and an ORACLE error code. This function does not support SQL state. This function can be called multiple times if there are more than one diagnostic record for an error.
The error handle is originally allocated with a call to OCIHandleAlloc().
The following sample code demonstrates how you can use OCIErrorGet() in an error-handling routine. This routine prints out the type of status code returned by an OCI function, and if an error occurred, OCIErrorGet() retrieves the text of the message, which is printed.
static void checkerr(errhp, status)
OCIError *errhp;
sword status;
{
text errbuf[512];
ub4 buflen;
ub4 errcode;
switch (status)
{
case OCI_SUCCESS:
break;
case OCI_SUCCESS_WITH_INFO:
printf("ErrorOCI_SUCCESS_WITH_INFO\n");
break;
case OCI_NEED_DATA:
printf("ErrorOCI_NEED_DATA\n");
break;
case OCI_NO_DATA:
printf("ErrorOCI_NO_DATA\n");
break;
case OCI_ERROR:
OCIErrorGet ((dvoid *) errhp, (ub4) 1, (text *) NULL, &errcode,
errbuf, (ub4) sizeof(errbuf), (ub4) OCI_HTYPE_ERROR);
printf("Error%s\n", errbuf);
break;
case OCI_INVALID_HANDLE:
printf("ErrorOCI_INVALID_HANDLE\n");
break;
case OCI_STILL_EXECUTING:
printf("ErrorOCI_STILL_EXECUTE\n");
break;
case OCI_CONTINUE:
printf("ErrorOCI_CONTINUE\n");
break;
default:
break;
}
}
This call returns a pointer to an allocated and initialized handle.
sword OCIHandleAlloc ( CONST dvoid *parenth, dvoid **hndlpp, ub4 type, size_t xtramem_sz, dvoid **usrmempp );
An environment handle.
Returns a handle.
Specifies the type of handle to be allocated. The allowed types are:
Specifies an amount of user memory to be allocated.
Returns a pointer to the user memory of size xtramem_sz allocated by the call for the user.
Returns a pointer to an allocated and initialized handle, corresponding to the type specified in type. A non-NULL handle is returned on success. All handles are allocated with respect to an environment handle which is passed in as a parent handle.
No diagnostics are available on error. This call returns OCI_SUCCESS if successful, or OCI_INVALID_HANDLE if an error occurs.
Handles must be allocated using OCIHandleAlloc() before they can be passed into an OCI call.
To allocate and initialize an environment handle, call OCIEnvInit().
See Also: For more information about using the xtramem_sz parameter for user memory allocation, refer to "User Memory Allocation" on page 2-12.
The following sample code shows OCIHandleAlloc() being used to allocate a variety of handles at the beginning of an application:
OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4)
OCI_HTYPE_ERROR, 0, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4)
OCI_HTYPE_SERVER, 0, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4)
OCI_HTYPE_SVCCTX, 0, (dvoid **) &tmp);
This call explicitly deallocates a handle.
sword OCIHandleFree ( dvoid *hndlp, ub4 type );
A handle allocated by OCIHandleAlloc().
Specifies the type of storage to be freed. The specific types are:
This call frees up storage associated with a handle, corresponding to the type specified in the type parameter.
This call returns either OCI_SUCCESS or OCI_INVALID_HANDLE.
All handles may be explicitly deallocated. The OCI will deallocate a child handle if the parent is deallocated.
OCIHandleAlloc(), OCIEnvInit()
Initializes the OCI process environment.
sword OCIInitialize ( ub4 mode, CONST dvoid *ctxp, CONST dvoid *(*malocfp) (/* dvoid *ctxp, size_t size _*/), CONST dvoid *(*ralocfp) (/*_ dvoid *ctxp, dvoid *memptr, size_t newsize _*/), CONST void (*mfreefp) (/*_ dvoid *ctxp, dvoid *memptr _*/));
Specifies initialization of the mode. The valid modes are:
User defined context for the memory call back routines.
User-defined memory allocation function. If mode is OCI_THREADED, this memory allocation routine must be thread safe.
Context pointer for the user-defined memory allocation function.
size (IN)Size of memory to be allocated by the user-defined memory allocation function
ralocfp (IN)User-defined memory re-allocation function. If mode is OCI_THREADED, this memory allocation routine must be thread safe.
Context pointer for the user-defined memory reallocation function.
memptr (IN/OUT)Pointer to memory block
newsize (IN)New size of memory to be allocated
mfreefp (IN)User-defined memory free function. If mode is OCI_THREADED, this memory free routine must be thread safe.
Context pointer for the user-defined memory free function.
memptr (IN/OUT)Pointer to memory to be freed
This call initializes the OCI process environment.
OCIInitialize() must be invoked before any other OCI call.
This function provides the ability for the application to define its own memory management functions through callbacks. If the application has defined such functions (i.e., memory allocation, memory re-allocation, memory free), they should be registered using the callback parameters in this function.
These memory callbacks are optional. If the application passes NULL values for the memory callbacks in this function, the default process memory allocation mechanism is used.
The following statement shows an example of how to call OCIInitialize() in both threaded and object mode, with no user-defined memory functions:
OCIInitialize((ub4) OCI_THREADED | OCI_OBJECT, (dvoid *)0,
(dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 );
Converts a V7 Lda_Def to a V8 service context handle.
sword OCILdaToSvcCtx ( OCISvcCtx **svchpp, OCIError *errhp, Lda_Def *ldap );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The Oracle7 logon data area returned by OCISvcCtxToLda() from this service context.
Converts an Oracle7 Lda_Def to an Oracle8 service context handle. The action of this call can be reversed by passing the resulting service context handle to the OCISvcCtxToLda() function.
If the Service context has been converted to an Lda_Def, only Oracle7 calls may be used. It is illegal to make Oracle8 OCI calls without first resetting the Lda_Def to a service context.
The OCI_ATTR_IN_V8_MODE attribute of the server handle or service context handle enables an application to determine whether the application is currently in Oracle7 mode or Oracle8 mode. See Appendix B, "Handle and Descriptor Attributes", for more information.
Appends a LOB value at the end of another LOB as specified.
sword OCILobAppend ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *dst_locp, OCILobLocator *src_locp );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
An internal LOB locator uniquely referencing the destination LOB. This locator must be a locator that was obtained from the server specified by svchp.
An internal LOB locator uniquely referencing the source LOB. This locator must be a locator that was obtained from the server specified by svchp.
Appends a LOB value at the end of another LOB as specified. The data is copied from the source to the destination at the end of the destination. The source and destination LOBs must already exist. The destination LOB is extended to accommodate the newly written data.
It is an error to extend the destination LOB beyond the maximum length allowed (i.e., 4 gigabytes) or to try to copy from a NULL LOB.
Both the source and the destination LOB locators must be of the same type (i.e., they must both be BLOBs or both be CLOBs). LOB buffering must not be enabled for either type of locator.
This function does not accept a FILE locator as the source or the destination.
OCILobTrim(), OCILobWrite(), OCILobCopy(), OCIErrorGet()
Assigns one LOB/FILE locator to another.
sword OCILobAssign ( OCIEnv *envhp, OCIError *errhp, CONST OCILobLocator *src_locp, OCILobLocator **dst_locpp );
OCI environment handle.
The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
LOB/FILE locator to copy from.
LOB/FILE locator to copy to. The caller must have allocated space for the destination locator by calling OCIDescriptorAlloc().
Assign source locator to destination locator. After the assignment, both locators refer to the same LOB value. For internal LOBs, the source locator's LOB value gets copied to the destination locator's LOB value only when the destination locator gets stored in the table. Therefore, issuing a flush of the object containing the destination locator will copy the LOB value.
For FILEs, only the locator that refers to the file is copied to the table. The OS file itself is not copied.
It is an error to assign a FILE locator to an internal LOB locator, and vice versa.
If the source locator is for an internal LOB that was enabled for buffering, and the source locator has been used to modify the LOB data through the LOB buffering subsystem, and the buffers have not been flushed since the write, then the source locator may not be assigned to the destination locator. This is because only one locator per LOB may modify the LOB data through the LOB buffering subsystem.
The value of the input destination locator must either be NULL, or it must have already been allocated with a call to OCIDescriptorAlloc(). For example, assume the following declarations:
OCILobLocator *source_loc = (OCILobLocator *) 0; OCILobLocator *dest_loc = (OCILobLocator *) 0;
An application could allocate the source_loc locator as follows:
if (OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &source_loc,
(ub4) OCI_DTYPE_LOB, (size_t) 0, (dvoid **) 0)) handle_error;
Assume that it then selects a LOB from a table into the source_loc in order to initialize it. The application could then do one of the following to assign the value of source_loc to dest_loc:
dest_loc and copy the source into it:
if (OCILobAssign(envhp, errhp, source_loc, &dest_loc)) handle_error;
dest_loc, and pass the preallocated destination locator to OCILobAssign():
if (OCIDescriptorAlloc((dvoid *) envhp, (dvoid **) &dest_loc,
(ub4)OCI_DTYPE_LOB, (size_t) 0, (dvoid **) 0)) handle_error; if (OCILobAssign(envhp, errhp, source_loc, &dest_loc)) handle_error;
OCIErrorGet(), OCILobIsEqual(), OCILobLocatorIsInit(), OCILobEnableBuffering()
Gets the LOB locator's character set form, if any.
sword OCILobCharSetForm ( OCIEnv *envhp, OCIError *errhp, CONST OCILobLocator *locp, ub1 *csfrm );
OCI environment handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
LOB locator for which to get the character set form.
Character set form of the input LOB locator. If the input locator is for a BLOB or a BFILE, csfrm is set to 0 since there is no concept of a character set for binary LOBs/FILEs. The caller must allocate space for the csfrm ub1.
Returns the character set form of the input LOB locator in the csfrm output parameter. This function makes sense only for character LOBs (i.e., CLOBs and NCLOBs).
OCIErrorGet(), OCILobCharSetId(), OCILobLocatorIsInit()
Gets the LOB locator's character set ID, if any.
sword OCILobCharSetId ( OCIEnv *envhp, OCIError *errhp, CONST OCILobLocator *locp, ub2 *csid );
OCI environment handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
LOB locator for which to get the character set ID.
Character set ID of the input LOB locator. If the input locator is for a BLOB or a BFILE, csid is set to 0 since there is no concept of a character set for binary LOBs/FILEs. The caller must allocate space for the csid ub2.
Returns the character set ID of the input LOB locator in the csid output parameter.
This function makes sense only for character LOBs (i.e., CLOBs, NCLOBs).
OCIErrorGet(), OCILobCharSetForm(), OCILobLocatorIsInit()
Copies all or a portion of a LOB value into another LOB value
sword OCILobCopy ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *dst_locp, OCILobLocator *src_locp, ub4 amount, ub4 dst_offset, ub4 src_offset );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
An internal LOB locator uniquely referencing the destination LOB. This locator must be a locator that was obtained from the server specified by svchp.
An internal LOB locator uniquely referencing the source LOB. This locator must be a locator that was obtained from the server specified by svchp.
The maximum number of characters or bytes, as appropriate, to be copied from the source LOB to the destination LOB.
This is the absolute offset for the destination LOB. For character LOBs it is the number of characters from the beginning of the LOB at which to begin writing. For binary LOBs it is the number of bytes from the beginning of the LOB from which to begin writing. The offset starts at 1.
This is the absolute offset for the source LOB. For character LOBs it is the number of characters from the beginning of the LOB, for binary LOBs it is the number of bytes. Starts at 1.
Copies all or a portion of an internal LOB value into another internal LOB as specified. The data is copied from the source to the destination. The source (src_locp) and the destination (dst_locp) LOBs must already exist.
If the data already exists at the destination's start position, it is overwritten with the source data. If the destination's start position is beyond the end of the current data, zero-byte fillers (for BLOBs) or spaces (for CLOBs) are written into the destination LOB from the end of the current data to the beginning of the newly written data from the source. The destination LOB is extended to accommodate the newly written data if it extends beyond the current length of the destination LOB. It is an error to extend the destination LOB beyond the maximum length allowed (i.e., 4 gigabytes) or to try to copy from a NULL LOB.
Both the source and the destination LOB locators must be of the same type (i.e., they must both be BLOBs or both be CLOBs). LOB buffering must not be enabled for either locator.
This function does not accept a FILE locator as the source or the destination.
The amount parameter indicates the maximum amount to copy. If the end of the source LOB is reached before the specified amount is copied, the operation terminates without error. This makes it possible to copy from a starting offset to the end of the LOB without first needing to determine the length of the LOB.
OCIErrorGet(), OCILobAppend(), OCILobTrim(), OCILobWrite()
Disable LOB buffering for the input locator.
sword OCILobDisableBuffering ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
An internal LOB locator uniquely referencing the LOB.
Disables LOB buffering for the input internal LOB locator. The next time data is read from or written to the LOB through the input locator, the LOB buffering subsystem is not used. Note that this call does not implicitly flush the changes made in the buffering subsystem. The user must explicitly call OCILobFlushBuffer() to do this.
This function does not accept a FILE locator.
OCILobEnableBuffering(), OCIErrorGet(), OCILobFlushBuffer()
Enable LOB buffering for the input locator.
sword OCILobEnableBuffering ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
An internal LOB locator uniquely referencing the LOB.
Enables LOB buffering for the input internal LOB locator. The next time data is read from or written to the LOB through the input locator, the LOB buffering subsystem is used.
Once LOB buffering is enabled for a locator, if that locator is passed to one of the following routines, an error is returned: OCILobCopy(), OCILobAppend(), OCILobErase(), OCILobGetLength(), OCILobTrim(), or OCILobLoadFromFile().
This function does not accept a FILE locator.
OCILobDisableBuffering(), OCIErrorGet(), OCILobWrite(), OCILobRead(), OCILobFlushBuffer()
Erases a specified portion of the LOB data starting at a specified offset.
sword OCILobErase ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp, ub4 *amount, ub4 offset );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
An internal LOB locator that uniquely references the LOB. This locator must be a locator that was obtained from the server specified by svchp.
On IN, the number of characters/bytes to erase. On OUT, the actual number of characters/bytes erased.
Absolute offset from the beginning of the LOB value from which to start erasing data. Starts at 1.
Erases a specified portion of the internal LOB data starting at a specified offset. The actual number of characters/bytes erased is returned. The actual number of characters/bytes and the requested number of characters/bytes will differ if the end of the LOB value is reached before erasing the requested number of characters/bytes.
Note: For BLOBs, erasing means that zero-byte fillers overwrite the existing LOB value. For CLOBs, erasing means that spaces overwrite the existing LOB value.
If the LOB is NULL, this routine will indicate that 0 characters/bytes were erased.
This function is valid only for internal LOBs; FILEs are not allowed.
OCIErrorGet(), OCILobRead(), OCILobWrite()
Closes a previously opened FILE.
sword OCILobFileClose ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *filep );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
A pointer to a FILE locator that refers to the FILE to be closed.
Closes a previously opened FILE. It is an error if this function is called for an internal LOB. No error is returned if the FILE exists but is not opened.
This function is only meaningful the first time it is called for a particular FILE locator. Subsequent calls to this function using the same FILE locator have no effect.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCIErrorGet(), OCILobFileCloseAll(), OCILobFileExists()
Closes all open FILEs on a given service context.
sword OCILobFileCLoseAll ( OCISvcCtx *svchp, OCIError *errhp );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
Closes all open FILEs on a given service context.
It is an error to call this function for an internal LOB.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCILobFileClose(), OCIErrorGet(), OCILobFileExists(), OCILobFileIsOpen()
Tests to see if the FILE exists on the server's OS
sword OCILobFileExists ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *filep, boolean *flag );
The OCI service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
Pointer to the FILE locator that refers to the file.
Returns TRUE if the FILE exists on the server; FALSE if it does not.
Checks to see if the FILE exists on the server's file system.
It is an error to call this function for an internal LOB.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCIErrorGet(), OCILobFileClose(), OCILobFileCloseAll(), OCILobFileIsOpen()
Gets the FILE locator's directory alias and file name.
sword OCILobFileGetName ( OCIEnv *envhp, OCIError *errhp, CONST OCILobLocator *filep, text *dir_alias, ub2 *d_length, text *filename, ub2 *f_length );
OCI environment handle.
The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
FILE locator for which to get the directory alias and file name.
Buffer into which the directory alias name is placed. The caller must allocate enough space for the directory alias name. The maximum length for the directory alias is 30 bytes.
Serves the following purposes
Buffer into which the file name is placed. The caller must allocate enough space for the file name. The maximum length for the file name is 255 bytes.
Serves the following purposes
Returns the directory alias and file name associated with this FILE locator.
It is an error to call this function for an internal LOB.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCILobFileSetName(), OCIErrorGet()
Tests to see if the FILE is open
sword OCILobFileIsOpen ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *filep, boolean *flag );
The OCI service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
Pointer to the FILE locator being examined.
Returns TRUE if the FILE was opened using this particular locator; FALSE if it was not.
Checks to see if a file on the server was opened with the filep FILE locator.
It is an error to call this function for an internal LOB.
If the input FILE locator was never passed to the OCILobFileOpen() command, the file is considered not to be opened by this locator. However, a different locator may have the file open. Openness is associated with a particular locator.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCIErrorGet(), OCILobFileClose(), OCILobFileCloseAll()
Opens a FILE for read-only access.
sword OCILobFileOpen ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *filep, ub1 mode );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
The FILE to open. It is an error if the locator does not refer to a FILE.
Mode in which to open the file. The only valid mode is OCI_FILE_READONLY.
Opens a FILE. The FILE can be opened for read-only access. FILEs may not be written through Oracle. It is an error to call this function for an internal LOB.
This function is only meaningful the first time it is called for a particular FILE locator. Subsequent calls to this function using the same FILE locator have no effect.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCILobFileClose(), OCIErrorGet(), OCILobFileIsOpen(), OCILobFileSetName()
Sets the directory alias and file name in the FILE locator.
sword OCILobFileSetName ( OCIEnv *envhp, OCIError *errhp, OCILobLocator **filepp, CONST text *dir_alias, ub2 d_length, CONST text *filename, ub2 f_length );
OCI environment handle.
The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
FILE locator for which to set the directory alias and file name.
Buffer that contains the directory alias name to set in the FILE locator.
Length of the input dir_alias parameter.
Buffer that contains the file name to set in the FILE locator.
Length of the input filename parameter.
Sets the directory alias and file name in the FILE locator.
It is an error to call this function for an internal LOB.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
OCILobFileGetName(), OCIErrorGet()
Flush/write all buffers for this lob to the server.
sword OCILobFlushBuffer ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp ub4 flag );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
An internal locator uniquely referencing the LOB.
When set to OCI_LOB_BUFFER_FREE, the buffer resources for the LOB are freed after the flush. See comments below.
Flushes to the server, changes made to the buffering subsystem that are associated with the LOB referenced by the input locator. This routine will actually write the data in the buffer to the LOB in the database. LOB buffering must have already been enabled for the input LOB locator.
The flush operation, by default, does not free the buffer resources for reallocation to another buffered LOB operation. However, if you want to free the buffer explicitly, you can set the flag parameter to OCI_LOB_BUFFER_FREE.
The effects of freeing the buffer are mostly transparent to the user, except that the next access to the same range in the LOB involves a round-trip to the server, and also the cost of acquiring buffer resources and initializing it with the data read from the LOB. This option is intended for the following situations:
OCILobEnableBuffering(), OCIErrorGet(), OCILobWrite(), OCILobRead(), OCILobDisableBuffering()
Gets the length of a LOB/FILE.
sword OCILobGetLength ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp, ub4 *lenp );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
A LOB/FILE locator that uniquely references the LOB/FILE. For internal LOBs, this locator must be a locator that was obtained from the server specified by svchp. For FILEs, the locator can be set via OCILobFileSetName(), via a SELECT statement, or via OCIObjectPin.
On output, it is the length of the LOB/FILE if the LOB/FILE is not NULL for character LOBs it is the number of characters, for binary LOBs and BFILEs it is the number of bytes in the LOB/FILE.
Gets the length of a LOB/FILE. If the LOB/FILE is NULL, the length is undefined.
The length of a FILE includes the EOF, if it exists.
The length is expressed in terms of bytes for BLOBs and BFILEs, and in terms of characters for CLOBs. The length of an empty internal LOB is zero.
Note: Any zero-byte or space fillers in the LOB written by previous calls to OCILobErase() or OCILobWrite() are also included in the length count.
OCIErrorGet(), OCILobFileSetName(), OCILobRead(), OCILobWrite(), OCILobCopy(), OCILobAppend(), OCILobLoadFromFile()
Compares two LOB/FILE locators for equality.
sword OCILobIsEqual ( OCIEnv *envhp, CONST OCILobLocator *x, CONST OCILobLocator *y, boolean *is_equal );
The OCI environment handle.
LOB locator to compare.
LOB locator to compare.
TRUE, if the LOB locators are equal; FALSE if they are not.
Compares the given LOB/FILE locators for equality. Two LOB/FILE locators are equal if and only if they both refer to the same LOB/FILE value.
Two NULL locators are considered not equal by this function.
OCILobAssign(), OCILobLocatorIsInit()
Load/copy all or a portion of the file into an internal LOB.
sword OCILobLoadFromFile ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *dst_locp, OCILobLocator *src_locp, ub4 amount, ub4 dst_offset, ub4 src_offset );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
A locator uniquely referencing the destination internal LOB which may be of type BLOB, CLOB, or NCLOB.
A locator uniquely referencing the source FILE.
The maximum number of bytes to be loaded.
This is the absolute offset for the destination LOB. For character LOBs it is the number of characters from the beginning of the LOB at which to begin writing. For binary LOBs it is the number of bytes from the beginning of the LOB from which to begin reading. The offset starts at 1.
This is the absolute offset for the source FILE. It is the number of bytes from the beginning of the FILE. The offset starts at 1.
Loads/copies a portion or all of a FILE value into an internal LOB as specified. The data is copied from the source FILE to the destination internal LOB (BLOB/CLOB). No character set conversions are performed when copying the FILE data to a CLOB/NCLOB. Therefore, the FILE data must already be in the same character set as the CLOB/NCLOB in the database. No error checking is performed to verify this.
The source (src_locp) and the destination (dst_locp) LOBs must already exist. If the data already exists at the destination's start position, it is overwritten with the source data. If the destination's start position is beyond the end of the current data, zero-byte fillers (for BLOBs) or spaces (for CLOBs) are written into the destination LOB from the end of the data to the beginning of the newly written data from the source. The destination LOB is extended to accommodate the newly written data if it extends beyond the current length of the destination LOB.
It is an error to extend the destination LOB beyond the maximum length allowed (4 gigabytes) or to try to copy from a NULL FILE.
The amount parameter indicates the maximum amount to load. If the end of the source FILE is reached before the specified amount is loaded, the operation terminates without error. This makes it possible to load from a starting offset to the end of the FILE without first needing to determine the length of the file.
OCIErrorGet(), OCILobAppend(), OCILobWrite(), OCILobTrim(), OCILobCopy(), OCILobGetLength()
Tests to see if a given LOB/FILE locator is initialized.
sword OCILobLocatorIsInit ( OCIEnv *envhp, OCIError *errhp, CONST OCILobLocator *locp, boolean *is_initialized );
OCI environment handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
The LOB/FILE locator being tested
Returns TRUE if the given LOB/FILE locator is initialized; FALSE if it is not.
Tests to see if a given LOB/FILE locator is initialized.
Internal LOB locators can be initialized by one of the following methods:
FILE locators can be initialized by one of the following methods:
OCIErrorGet(), OCILobIsEqual()
Reads a portion of a LOB/FILE, as specified by the call, into a buffer.
sword OCILobRead ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp, ub4 *amtp, ub4 offset, dvoid *bufp, ub4 bufl, dvoid *ctxp, OCICallbackLobRead (cbfp) ( dvoid *ctxp, CONST dvoid *bufp, ub4 len, ub1 piece ) ub2 csid, ub1 csfrm );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
A LOB/FILE locator that uniquely references the LOB/FILE. This locator must be a locator that was obtained from the server specified by svchp.
On input, the number of characters (for CLOBs or NCLOBs) or bytes (for BLOBs and BFILEs) to be read. On output, the actual number of bytes or characters read.
If the amount of bytes to be read is larger than the buffer length it is assumed that the LOB is being read in a streamed mode from the input offset until the end of the LOB, or until the specified number of bytes have been read, whichever comes first. On input if this value is 0, then the data shall be read in streamed mode from the input offset until the end of the LOB.
The streamed mode (implemented with either polling or callbacks) reads the LOB value sequentially from the input offset.
If the data is read in pieces, *amtp always contains the length of the piece just read.
If a callback function is defined, then this callback function will be invoked each time bufl bytes are read off the pipe. Each piece will be written into bufp.
If the callback function is not defined, then the OCI_NEED_DATA error code will be returned. The application must call OCILobRead() over and over again to read more pieces of the LOB until the OCI_NEED_DATA error code is not returned. The buffer pointer and the length can be different in each call if the pieces are being read into different sizes and locations.
On input, this is the absolute offset from the beginning of the LOB value. For character LOBs (CLOBs, NCLOBs) it is the number of characters from the beginning of the LOB, for binary LOBs/FILEs it is the number of bytes. The first position is 1.
The pointer to a buffer into which the piece will be read. The length of the allocated memory is assumed to be bufl.
The length of the buffer in octets. This value will differ from the amtp value in the following cases:
The context for the callback function. Can be NULL.
A callback that may be registered to be called for each piece. If this is NULL, then OCI_NEED_DATA will be returned for each piece.
The callback function must return OCI_CONTINUE for the read to continue. If any other error code is returned, the LOB read is aborted.
The context for the callback function. Can be NULL.
bufp (IN/OUT)A buffer pointer for the piece.
len (IN)The length of the current piece in bufp.
piece (IN)Which piece: OCI_FIRST_PIECE, OCI_NEXT_PIECE or OCI_LAST_PIECE.
csid (IN)The character set ID of the buffer data.
The character set form of the buffer data.
Reads a portion of a LOB/FILE as specified by the call into a buffer. It is an error to try to read from a NULL LOB/FILE.
Note: When reading or writing LOBs, the character set form (csfrm) specified should match the form of the locator itself.
For FILEs, the OS file must already exist on the server, and it must have been opened via OCILobFileOpen() using the input locator. Oracle must have permission to read the OS file, and the user must have read permission on the directory object.
When using the polling mode for OCILobRead(), the first call needs to specify values for offset and amtp, but on subsequent polling calls to OCILobRead(), the user need not specify these values.
See Also: For more information about FILEs, refer to the description of BFILEs in the Oracle8 Application Developer's Guide.
For a code sample showing the use of LOB reads and writes, refer to "Example 5, CLOB/BLOB Operations" on page D-76.
For general information about piecewise OCI operations, refer to "Run Time Data Allocation and Piecewise Operations" on page 7-16.
OCIErrorGet(), OCILobWrite(), OCILobFileSetName()
Trims/truncates the LOB value to a shorter length.
sword OCILobTrim ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp, ub4 newlen );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
An internal LOB locator that uniquely references the LOB. This locator must be a locator that was obtained from the server specified by svchp.
The new length of the LOB value, which must be less than or equal to the current length.
Trims the LOB data to a specified shorter length.
The function returns an error if newlen is greater than the current LOB length.
This function is valid only for internal LOBs. FILEs are not allowed.
OCIErrorGet(). OCILobErase(), OCILobAppend(), OCILobCopy(), OCILobWrite()
Writes a buffer into a LOB
sword OCILobWrite ( OCISvcCtx *svchp, OCIError *errhp, OCILobLocator *locp, ub4 *amtp, ub4 offset, dvoid *bufp, ub4 buflen, ub1 piece, dvoid *ctxp, OCICallbackLobWrite (cbfp) (/*_ dvoid *ctxp, dvoid *bufp, ub4 *lenp, ub1 *piecep */) ub2 csid, ub1 csfrm );
The service context handle.
Error handle. The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
An internal LOB locator that uniquely references the LOB. This locator must be a locator that was obtained from the server specified by svchp.
On input, takes the number of characters or bytes to be written. On output, returns the actual number of bytes or characters written.
If the amount is specified on input, and the data is written in pieces, *amtp will contain the total length of the pieces written at the end of the call (last piece written) and is undefined in between. (Note it is different from the piecewise read case). An error is returned if that amount is not sent to the server.
If amtp is zero, then streaming mode is assumed, and data is written until the user specifies OCI_LAST_PIECE.
On input, it is the absolute offset from the beginning of the LOB value. For character LOBs it is the number of characters from the beginning of the LOB, for binary LOBs it is the number of bytes. The first position is 1.
The pointer to a buffer from which the piece will be written. The length of the allocated memory is assumed to be the value passed in buflen. Even if the data is being written in pieces using the polling method, bufp must contain the first piece of the LOB when this call is invoked. If a callback is provided, bufp must not be used to provide data or an error will result.
the length of the buffer in bytes. This value will differ from the amtp value in the following cases:
Note: This parameter assumes an 8-bit byte. If your platform uses a longer byte, the value of buflen must be adjusted accordingly.
piece (IN)Which piece of the buffer is being written. The default value for this parameter is OCI_ONE_PIECE, indicating the buffer will be written in a single piece.
The following other values are also possible for piecewise or callback mode: OCI_FIRST_PIECE, OCI_NEXT_PIECE and OCI_LAST_PIECE.
The context for the callback function. Can be NULL.
A callback that may be registered to be called for each piece in a piecewise write. If this is NULL, the standard polling method will be used.
The callback function must return OCI_CONTINUE for the write to continue. If any other error code is returned, the LOB write is aborted. The callback takes the following parameters:
The context for the callback function. Can be NULL.
bufp (IN/OUT)A buffer pointer for the piece.
lenp (IN/OUT)The length of the buffer in octets (IN),
and the length of current piece in bufp in octets (OUT).
piecep (OUT)Which piece: OCI_NEXT_PIECE or OCI_LAST_PIECE.
csid (IN)The LOB character set ID of the buffer data.
The LOB character set form of the buffer data.
Writes a buffer into a LOB as specified. If LOB data already exists it is overwritten with the data stored in the buffer.
The buffer can be written to the LOB in a single piece with this call, or it can be provided piecewise using callbacks or a standard polling method.
Note: When reading or writing LOBs, the character set form (csfrm) specified should match the form of the locator itself.
When using the polling mode for OCILobWrite(), the first call needs to specify values for offset and amtp, but on subsequent polling calls to OCILobWrite(), the user need not specify these values.
If the value of the piece parameter is OCI_FIRST_PIECE, data may need to be provided through callbacks or polling.
If a callback function is defined in the cbfp parameter, then this callback function will be invoked to get the next piece after a piece is written to the pipe. Each piece will be written from bufp.
If no callback function is defined, then OCILobWrite() returns the OCI_NEED_DATA error code. The application must call OCILobWrite() again to write more pieces of the LOB. In this mode, the buffer pointer and the length can be different in each call if the pieces are of different sizes and from different locations.
A piece value of OCI_LAST_PIECE terminates the piecewise write, regardless of whether the polling or callback method is used.
If the amount of data passed to Oracle (through either input mechanism) is less than the amount specified by the amtp parameter, an ORA-22993 error is returned.
This function is valid for internal LOBs only. FILEs are not allowed, since they are read-only.
See Also: For a code sample showing the use of LOB reads and writes, refer to "Example 5, CLOB/BLOB Operations" on page D-76.
For general information about piecewise OCI operations, refer to "Run Time Data Allocation and Piecewise Operations" on page 7-16.
OCIErrorGet(), OCILobRead(), OCILobAppend(), OCILobCopy()
This function is used to terminate a connection and session created with OCILogon().
sword OCILogoff ( OCISvcCtx *svchp OCIError *errhp );
The service context handle which was used in the call to OCILogon().
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
This call is used to terminate a session and connection which were created with OCILogon(). This call implicitly deallocates the server, user session, and service context handles.
Note: For more information on logging on and off in an application, refer to the section "Application Initialization, Connection, and Session Creation" on page 2-18.
This function is used to create a simple logon session.
sword OCILogon ( OCIEnv *envhp, OCIError *errhp, OCISvcCtx **svchp, CONST text *username, ub4 uname_len, CONST text *password, ub4 passwd_len, CONST text *dbname, ub4 dbname_len );
The OCI environment handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The service context pointer.
The username.
The length of username.
The user's password.
The length of password.
The name of the database to connect to.
The length of dbname.
This function is used to create a simple logon session for an application.
Note: Users requiring more complex sessions (e.g., TP monitor applications) should refer to the section "Application Initialization, Connection, and Session Creation" on page 2-18.
This call allocates the error and service context handles which are passed to it.
This call also implicitly allocates server and user session handles associated with the session. These handles can be retrieved by calling OCIAQEnq() on the service context handle.
Returns a descriptor of a parameter specified by position in the describe handle or statement handle.
sword OCIParamGet ( CONST dvoid *hndlp, ub4 htype, OCIError *errhp, dvoid **parmdpp, ub4 pos );
A statement handle or describe handle. The OCIParamGet() function will return a parameter descriptor for this handle.
the type of the handle passed in the handle parameter. Valid types are
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
A descriptor of the parameter at the position given in the pos parameter.
Position number in the statement handle or describe handle. A parameter descriptor will be returned for this position.
This call returns a descriptor of a parameter specified by position in the describe handle or statement handle. Parameter descriptors are always allocated internally by the OCI library. They are read-only.
OCI_NO_DATA may be returned if there are no parameter descriptors for this position.
See Appendix B, "Handle and Descriptor Attributes", for more detailed information about parameter descriptor attributes.
OCIAQEnq(), OCIAttrSet(), OCIParamSet()
Used to set a complex object retrieval descriptor into a complex object retrieval handle.
sword OCIParamSet ( dvoid *hndlp, ub4 htype, OCIError *errhp, CONST dvoid *dscp, ub4 dtyp, ub4 pos );
Handle pointer.
Handle type.
Error handle.
Complex object retrieval descriptor pointer.
Descriptor type. The descriptor type for a COR descriptor is OCI_DTYPE_COMPLEXOBJECTCOMP.
Position number.
This call sets a given complex object retrieval descriptor into a complex object retrieval handle.
The handle must have been previously allocated using OCIHandleAlloc(), and the descriptor must have been previously allocated using OCIDescriptorAlloc(). Attributes of the descriptor are set using OCIAttrSet().
For more information about complex object retrieval, see "Complex Object Retrieval" on page 8-21.
This call allows the password of an account to be changed.
sword OCIPasswordChange ( OCISvcCtx *svchp, OCIError *errhp, CONST text *user_name, ub4 usernm_len, CONST text *opasswd, ub4 opasswd_len, CONST text *npasswd, sb4 npasswd_len, ub4 mode );
A handle to a service context. The service context handle must be initialized and have a server context handle associated with it.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Specifies the user name. It points to a character string, whose length is specified in usernm_len. This parameter must be NULL if the service context has been initialized with an user session handle.
The length of the user name string specified in user_name. For a valid user name string, usernm_len must be non-zero.
Specifies the user's old password. It points to a character string, whose length is specified in opasswd_len.
The length of the old password string specified in opasswd. For a valid password string, opasswd_len must be non-zero.
Specifies the user's new password. It points to a character string, whose length is specified in npasswd_len which must be non-zero for a valid password string. If the password complexity verification routine is specified in the user's profile to verify the new password's complexity, the new password must meet the complexity requirements of the verification function.
Then length of the new password string specified in npasswd. For a valid password string, npasswd_len must be non-zero.
Can be OCI_DEFAULT and/or OCI_AUTH. If set to OCI_AUTH, the following happens:
This call allows the password of an account to be changed. This call is similar to OCISessionBegin() with the following differences:
This call is useful when the password of an account is expired and OCISessionBegin() returns an error or warning which indicates that the password has expired.
Creates an access path to a data source for OCI operations.
sword OCIServerAttach ( OCIServer *srvhp, OCIError *errhp, CONST text *dblink, sb4 dblink_len, ub4 mode );
An uninitialized server handle, which gets initialized by this call. Passing in an initialized server handle causes an error.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Specifies the database (server) to use. This parameter points to a character string which specifies a connect string or a service point. If the connect string is NULL, then this call attaches to the default host. The length of dblink is specified in dblink_len. The dblink pointer may be freed by the caller on return.
The length of the string pointed to by dblink. For a valid connect string name or alias, dblink_len must be non-zero.
Specifies the various modes of operation. For release 8.0, pass as OCI_DEFAULT. In this mode, calls made to the server on this server context are made in blocking mode.
This call is used to create an association between an OCI application and a particular server.
This call initializes a server context handle, which must have been previously allocated with a call to OCIHandleAlloc().
The server context handle initialized by this call can be associated with a service context through a call to OCIAttrSet(). Once that association has been made, OCI operations can be performed against the server.
If an application is operating against multiple servers, multiple server context handles can be maintained. OCI operations are performed against whichever server context is currently associated with the service context.
The following example demonstrates the use of OCIServerAttach(). This code segment allocates the server handle, makes the attach call, allocates the service context handle, and then sets the server context into it.
OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4)
OCI_HTYPE_SERVER, 0, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4)
OCI_HTYPE_SVCCTX, 0, (dvoid **) &tmp); /* set attribute server context in the service context */ OCIAttrSet( (dvoid *) svchp, (ub4) OCI_HTYPE_SVCCTX, (dvoid *) srvhp,
(ub4) 0, (ub4) OCI_ATTR_SERVER, (OCIError *) errhp);
Deletes an access to a data source for OCI operations.
sword OCIServerDetach ( OCIServer *srvhp, OCIError *errhp, ub4 mode );
A handle to an initialized server context, which gets reset to uninitialized state. The handle is not de-allocated.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Specifies the various modes of operation. The only valid mode is OCI_DEFAULT for the default mode.
This call deletes an access to data source for OCI operations, which was established by a call to OCIServerAttach().
Returns the version string of the Oracle server.
sword OCIServerVersion ( dvoid *hndlp, OCIError *errhp, text *bufp, ub4 bufsz ub1 hndltype );
The service context handle or the server context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The buffer in which the version information is returned.
The length of the buffer.
The type of handle passed to the function.
This call returns the version string of the Oracle server. For example, the following might be returned as the version string if your application is running against a 7.3.2 server:
Oracle7 Server Release 7.3.2.0.0 Production Release
PL/SQL Release 2.3.2.0.0 Production
CORE Version 3.5.2.0.0 Production
TNS for SEQUENT DYNIX/ptx: Version 2.3.2.0.0 Production
NLSRTL Version 3.2.2.0.0 Production
Creates a user session and begins a user session for a given server.
sword OCISessionBegin ( OCISvcCtx *svchp, OCIError *errhp, OCISession *usrhp, ub4 credt, ub4 mode );
A handle to a service context. There must be a valid server handle set in svchp.
An error handle to the retrieve diagnostic information.
A handle to an user session context, which is initialized by this call.
Specifies the type of credentials to use for establishing the user session. Valid values for credt are:
Specifies the various modes of operation. Valid modes are:
The OCISessionBegin() call is used to authenticate a user against the server set in the service context handle.
For Oracle8, OCISessionBegin() must be called for any given server handle before requests can be made against it. Also, OCISessionBegin() only supports authenticating the user for access to the Oracle server specified by the server handle in the service context. In other words, after OCIServerAttach() is called to initialize a server handle, OCISessionBegin() must be called to authenticate the user for that given server.
When OCISessionBegin() is called for the first time for a given server handle, the user session may not be created in migratable (OCI_MIGRATE) mode.
After OCISessionBegin() has been called for a server handle, the application may call OCISessionBegin() again to initialize another user session handle with different (or the same) credentials and different (or the same) operation modes. If an application wants to authenticate a user in OCI_MIGRATE mode, the service handle must already be associated with a non-migratable user handle. The user ID of that user handle becomes the ownership ID of the migratable user session. Every migratable session must have a non-migratable parent session.
If the OCI_MIGRATE mode is not specified, then the user session context can only ever be used with the same server handle set in svchp. If OCI_MIGRATE mode is specified, then the user authentication may be set with different server handles. However, the user session context may only be used with server handles which resolve to the same database instance. Security checking is done during session switching. A process or circuit is allowed to switch to a migratable session only if the ownership ID of the session matches the user ID of a non-migratable session currently connected to that same process or circuit, unless it is the creator of the session.
OCI_SYSDBA, OCI_SYSOPER, and OCI_PRELIM_AUTH may only be used with a primary user session context.
To provide credentials for a call to OCISessionBegin(), one of two methods are supported. The first is to provide a valid username and password pair for database authentication in the user session handle passed to OCISessionBegin(). This involves using OCIAttrSet() to set the OCI_ATTR_USERNAME and OCI_ATTR_PASSWORD attributes on the user session handle. Then OCISessionBegin() is called with OCI_CRED_RDBMS.
Note: When the user session handle is terminated using OCISessionEnd(), the username and password attributes remain unchanged and thus can be re-used in a future call to OCISessionBegin(). Otherwise, they must be reset to new values before the next OCISessionBegin() call.
The second type of credentials supported are external credentials. No attributes need to be set on the user session handle before calling OCISessionBegin(). The credential type is OCI_CRED_EXT. This is equivalent to the Oracle7 `connect /' syntax. If values have been set for OCI_ATTR_USERNAME and OCI_ATTR_PASSWORD, then these are ignored if OCI_CRED_EXT is used.
The following example demonstrates the use of OCISessionBegin(). This code segment allocates the user session handle, sets the username and password attributes, calls OCISessionBegin(), and then sets the user session into the service context.
/* allocate a user session handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&usrhp, (ub4)
OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"jessica",
(ub4)strlen("jessica"), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"doogie",
(ub4)strlen("doogie"), OCI_ATTR_PASSWORD, errhp); checkerr(errhp, OCISessionBegin (svchp, errhp, usrhp, OCI_CRED_RDBMS,
OCI_DEFAULT)); OCIAttrSet((dvoid *)svchp, (ub4)OCI_HTYPE_SVCCTX, (dvoid *)usrhp,
(ub4)0, OCI_ATTR_SESSION, errhp);
Terminates a user session context created by OCISessionBegin()
sword OCISessionEnd ( OCISvcCtx *svchp, OCIError *errhp, OCISession *usrhp, ub4 mode );
The service context handle. There must be a valid server handle and user session handle associated with svchp.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
De-authenticate this user. If this parameter is passed as NULL, the user in the service context handle is de-authenticated.
The only valid mode is OCI_DEFAULT.
The user security context associated with the service context is invalidated by this call. Storage for the user session context is not freed. The transaction specified by the service context is implicitly committed. The transaction handle, if explicitly allocated, may be freed if not being used.
Resources allocated on the server for this user are freed.
The user session handle may be reused in a new call to OCISessionBegin().
This call associates an application request with a server.
sword OCIStmtExecute ( OCISvcCtx *svchp, OCIStmt *stmtp, OCIError *errhp, ub4 iters, ub4 rowoff, CONST OCISnapshot *snap_in, OCISnapshot *snap_out, ub4 mode );
Service context handle.
An statement handle. It defines the statement and the associated data to be executed at the server. It is invalid to pass in a statement handle that has bind of data types only supported in release 8.0 when svchp points to an Oracle7 server.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The number of times this statement is executed for non-SELECT statements. For Select statements, if iters is non-zero, then defines must have been done for the statement handle. The execution fetches iters rows into these predefined buffers and prefetches more rows depending upon the prefetch row count. This function returns an error if iters=0 for non-SELECT statements.
The starting index from which the data in an array bind is relevant for this multiple row execution.
This parameter is optional. if supplied, must point to a snapshot descriptor of type OCI_DTYPE_SNAP. The contents of this descriptor must be obtained from the snap_out parameter of a previous call. The descriptor is ignored if the SQL is not a SELECT. This facility allows multiple service contexts to ORACLE to see the same consistent snapshot of the database's committed data. However, uncommitted data in one context is not visible to another context even using the same snapshot.
This parameter optional. if supplied, must point to a descriptor of type OCI_DTYPE_SNAP. This descriptor is filled in with an opaque representation which is the current ORACLE "system change number" suitable as a snap_in input to a subsequent call to OCIStmtExecute(). This descriptor should not be used longer than necessary in order to avoid "snapshot too old" errors.
The modes are:
This function is used to execute a prepared SQL statement. Using an execute call, the application associates a request with a server.
If a SELECT statement is executed, the description of the select-list is available implicitly as a response. This description is buffered on the client side for describes, fetches and define type conversions. Hence it is optimal to describe a select list only after an execute. See "Describing Select-List Items" on page 4-8 for more information.
Also for SELECT statements, some results are available implicitly. Rows will be received and buffered at the end of the execute. For queries with small row count, a prefetch causes memory to be released in the server if the end of fetch is reached, an optimization that may result in memory usage reduction. Set attribute call has been defined to set the number of rows to be prefetched per result set.
For SELECT statements, at the end of the execute, the statement handle implicitly maintains a reference to the service context on which it is executed. It is the user's responsibility to maintain the integrity of the service context. The implicit reference is maintained until the statement handle is freed or the fetch is cancelled or an end of fetch condition is reached.
Note: If output variables are defined for a SELECT statement before a call to OCIStmtExecute(), the number of rows specified by iters will be fetched directly into the defined output buffers and additional rows equivalent to the prefetch count will be prefetched. If there are no additional rows, then the fetch is complete without calling OCIStmtFetch().
Fetches rows from a query.
sword OCIStmtFetch ( OCIStmt *stmtp, OCIError *errhp, ub4 nrows, ub2 orientation, ub4 mode );
A statement (application request) handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Number of rows to be fetched from the current position.
For release 8.0, the only acceptable value is OCI_FETCH_NEXT, which is also the default value.
For release 8.0, pass as OCI_DEFAULT.
The fetch call is a local call, if prefetched rows suffice. However, this is transparent to the application. If LOB columns are being read, LOB locators are fetched for subsequent LOB operations to be performed on these locators. Prefetching is turned off if LONG columns are involved.
This function can return OCI_SUCCESS_WITH_INFO if the data is truncated or EOF is reached.
Gets the bind and indicator variable names.
sword OCIStmtGetBindInfo ( OCIStmt *stmtp, OCIError *errhp, ub4 size, ub4 startloc, sb4 *found, text *bvnp[], ub1 bvnl[], text *invp[], ub1 inpl[], ub1 dupl[], OCIBind *hndl[] );
The statement handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
The number of elements in each array.
Position of the bind variable at which to start getting bind information.
Abs(found) gives the total number of bind variables in the statement irrespective of the start position. Positive value if the number of bind variables returned is less than the size provided, otherwise negative.
Array of pointers to hold bind variable names.
Array to hold the length of the each bvnp element.
Array of pointers to hold indicator variable names.
Array of pointers to hold the length of the each invp element.
An array whose element value is 0 or 1 depending on whether the bind position is duplicate of another.
An array which returns the bind handle if binds have been done for the bind position. No handle is returned for duplicates.
This call returns information about bind variables after a statement has been prepared. This includes bind names, indicator names, and whether or not binds are duplicate binds. This call also returns an associated bind handle if there is one. The call sets the found parameter to the total number of bind variables and not just the number of distinct bind variables.
This function does not include SELECT INTO list variables, because they are not considered to be binds.
The statement must have been prepared with a call to OCIStmtPrepare() prior to this call.
This call is processed locally.
Returns piece information for a piecewise operation.
sword OCIStmtGetPieceInfo( CONST OCIStmt *stmtp, OCIError *errhp, dvoid **hndlpp, ub4 *typep, ub1 *in_outp, ub4 *iterp, ub4 *idxp, ub1 *piecep );
The statement when executed returned OCI_NEED_DATA.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
Returns a pointer to the bind or define handle of the bind or define whose runtime data is required or is being provided.
The type of the handle pointed to by hndlpp: OCI_HTYPE_BIND (for a bind handle) or OCI_HTYPE_DEFINE (for a define handle).
Returns OCI_PARAM_IN if the data is required for an IN bind value. Returns OCI_PARAM_OUT if the data is available as an OUT bind variable or a define position value.
Returns the row number of a multiple row operation.
The index of an array element of a PL/SQL array bind operation.
Returns one of the following defined values OCI_ONE_PIECE, OCI_FIRST_PIECE, OCI_NEXT_PIECE and OCI_LAST_PIECE.
When an execute/fetch call returns OCI_NEED_DATA to get/return a dynamic bind/define value or piece, OCIStmtGetPieceInfo() returns the relevant information: bind/define handle, iteration, index number and which piece.
See the section "Run Time Data Allocation and Piecewise Operations" on page 7-16 for more information about using OCIStmtGetPieceInfo().
OCIAQEnq(), OCIAQEnq(), OCIStmtExecute(), OCIStmtFetch(), OCIStmtSetPieceInfo()
This call prepares a SQL or PL/SQL statement for execution.
sword OCIStmtPrepare ( OCIStmt *stmtp, OCIError *errhp, CONST text *stmt, ub4 stmt_len, ub4 language, ub4 mode );
A statement handle.
An error handle to retrieve diagnostic information.
SQL or PL/SQL statement to be executed. Must be a null-terminated string. The pointer to the text of the statement must be available as long as the statement is executed, or data is fetched from it.
Length of the statement. Must not be zero.
Specifies V7, V8, or native syntax. Possible values are:
The only defined mode is OCI_DEFAULT for default mode.
An OCI application uses this call to prepare a SQL or PL/SQL statement for execution. The OCIStmtPrepare() call defines an application request.
This is a purely local call. Data values for this statement initialized in subsequent bind calls will be stored in a bind handle which will hang off this statement handle.
This call does not create an association between this statement handle and any particular server.
See the section "Preparing Statements" on page 4-4 for more information about using this call.
Sets piece information for a piecewise operation.
sword OCIStmtSetPieceInfo ( dvoid *hndlp, ub4 type, OCIError *errhp, CONST dvoid *bufp, ub4 *alenp, ub1 piece, CONST dvoid *indp, ub2 *rcodep );
The bind/define handle.
Type of the handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
A pointer to a storage containing the data value or the piece when it is an IN bind variable, otherwise bufp is a pointer to storage for getting a piece or a value for OUT binds and define variables. For named data types or REFs, a pointer to the object or REF is returned.
The length of the piece or the value.
The piece parameter. Valid values:
This parameter is used for IN bind variables only.
Indicator. A pointer to a sb2 value or pointer to an indicator structure for named data types (SQLT_NTY) and REFs (SQLT_REF), i.e., *indp is either an sb2 or a dvoid * depending upon the data type.
Return code.
When an execute call returns OCI_NEED_DATA to get a dynamic IN/OUT bind value or piece, OCIStmtSetPieceInfo() sets the piece information: the buffer, the length, which piece is currently being processed, the indicator, and the return code for this column.
For more information about using OCIStmtSetPieceInfo() see the section "Run Time Data Allocation and Piecewise Operations" on page 7-16.
OCIAQEnq(), OCIAQEnq(), OCIStmtExecute(), OCIStmtFetch(), OCIStmtGetPieceInfo()
Toggles between a V8 service context handle and a V7 Lda_Def.
sword OCISvcCtxToLda ( OCISvcCtx *srvhp, OCIError *errhp, Lda_Def *ldap );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
A Logon Data Area for Oracle7-style OCI calls which is initialized by this call.
Toggles between an Oracle8 service context handle and an Oracle7 Lda_Def.
This function can only be called after a service context has been properly initialized.
Once the service context has been translated to an Lda_Def, it can be used in release 7.x OCI calls (e.g., obindps(), ofen()).
Note: If there are multiple service contexts which share the same server handle, only one can be in Oracle7 mode at any time.
The action of this call can be reversed by passing the resulting Lda_Def to the OCILdaToSvcCtx() function.
The OCI_ATTR_IN_V8_MODE attribute of the server handle or service context handle enables an application to determine whether the application is currently in Oracle7 mode or Oracle8 mode. See Appendix B, "Handle and Descriptor Attributes", for more information.
Commits the transaction associated with a specified service context.
sword OCITransCommit ( OCISvcCtx *svchp, OCIError *errhp, ub4 flags );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
See the "Comments" section below.
The transaction currently associated with the service context is committed. If it is a global transaction that the server cannot commit, this call additionally retrieves the state of the transaction from the database to be returned to the user in the error handle.
If the application has defined multiple transactions, this function operates on the transaction currently associated with the service context. If the application is working with only the implicit local transaction created when database changes are made, that implicit transaction is committed.
If the application is running in the object mode, then the modified or updated objects in the object cache for this transaction are also flushed and committed.
The flags parameter is used for one-phase commit optimization in global transactions. If the transaction is non-distributed, the flags parameter is ignored, and OCI_DEFAULT can be passed as its value. OCI applications managing global transactions should pass a value of OCI_TRANS_TWOPHASE to the flags parameter for a two-phase commit. The default is one-phase commit.
Under normal circumstances, OCITransCommit() returns with a status indicating that the transaction has either been committed or rolled back. With global transactions, it is possible that the transaction is now in-doubt (i.e., neither committed nor aborted). In this case, OCITransCommit() attempts to retrieve the status of the transaction from the server. The status is returned.
The following example demonstrates the use of a simple local transaction, as described in the section "Simple Local Transactions" on page 7-4.
int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; OCIStmt *stmthp; dvoid *tmp; text sqlstmt[128]; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 0, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)srvhp, 0, OCI_ATTR_SERVER, errhp); OCILogon(envhp, errhp, &svchp, "SCOTT", strlen("SCOTT"), "TIGER", strlen("TIGER"), 0, 0); /* update scott.emp empno=7902, increment salary */ sprintf((char *)sqlstmt, "UPDATE EMP SET SAL = SAL + 1 WHERE EMPNO = 7902"); OCIStmtPrepare(stmthp, errhp, sqlstmt, strlen(sqlstmt), OCI_NTV_SYNTAX, 0); OCIStmtExecute(svchp, stmthp, errhp, 1, 0, 0, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* update scott.emp empno=7902, increment salary again, but rollback */ OCIStmtExecute(svchp, stmthp, errhp, 1, 0, 0, 0, 0); OCITransRollback(svchp, errhp, (ub4) 0); }
Detaches a transaction.
sword OCITransDetach ( OCISvcCtx *svchp, OCIError *errhp, ub4 flags );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
You must pass a value of OCI_DEFAULT for this parameter.
Detaches a global transaction from the service context handle. The transaction currently attached to the service context handle becomes inactive at the end of this call. The transaction may be resumed later by calling OCITransStart(), specifying a flags value of OCI_TRANS_RESUME.
When a transaction is detached, the value which was specified in the timeout parameter of OCITransStart() when the transaction was started is used to determine the amount of time the branch can remain inactive before being deleted by the server's PMON process.
Note: The transaction can be resumed by a different process than the one that detached it, provided that the transaction has the same authorization.
If this function is called before a transaction is actually started, this function is a no-op.
Causes the server to forget a heuristically completed global transaction.
sword OCITransForget ( OCISvcCtx *svchp, OCIError *errhp, ub4 flags );
The service context handle in which the transaction resides.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
You must pass OCI_DEFAULT for this parameter.
Forgets a heuristically completed global transaction. The server deletes the status of the transaction from the system's pending transaction table.
The XID of the transaction to be forgotten is set as an attribute of the transaction handle (OCI_ATTR_XID).
OCITransCommit(), OCITransRollback()
Prepares a transaction for commit.
sword OCITransPrepare ( OCISvcCtx *svchp, OCIError *errhp, ub4 flags );
The service context handle.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
You must pass OCI_DEFAULT for this parameter.
Prepares the specified global transaction for commit.
This call is valid only for global transactions.
The call returns OCI_SUCCESS_WITH_INFO if the transaction has not made any changes. The error handle will indicate that the transaction is read-only. The flag parameter is not currently used.
OCITransCommit(), OCITransForget()
Rolls back the current transaction.
sword OCITransRollback ( dvoid *svchp, OCIError *errhp, ub4 flags );
A service context handle. The transaction currently set in the service context handle is rolled back.
An error handle which can be passed to OCIErrorGet() for diagnostic information in the event of an error.
You must pass a value of OCI_DEFAULT for this parameter.
The current transaction- defined as the set of statements executed since the last OCITransCommit() or since OCISessionBegin()-is rolled back.
If the application is running under object mode then the modified or updated objects in the object cache for this transaction are also rolled back.
An error is returned if an attempt is made to roll back a global transaction that is not currently active.
Sets the beginning of a transaction.
sword OCITransStart ( OCISvcCtx *svchp, OCIError *errhp, uword timeout, ub4 flags );
The service context handle. The transaction context in the service context handle is initialized at the end of the call if the flag specified a new transaction to be started.
The OCI error handle. If there is an error, it is recorded in err and this function returns OCI_ERROR. Diagnostic information can be obtained by calling OCIErrorGet().
The time, in seconds, to wait for a transaction to become available for resumption when OCI_TRANS_RESUME is specified. When OCI_TRANS_NEW is specified, the timeout parameter indicates the number of seconds the transaction can be inactive before it is automatically aborted by the system. A transaction is inactive between the time it is detached (with OCITransDetach()) and the time it is resumed with OCITransStart().
Specifies whether a new transaction is being started or an existing transaction is being resumed. Also specifies serializiability or read-only status. More than a single value can be specified. By default, a read/write transaction is started. The flag values are:
This function sets the beginning of a global or serializable transaction. The transaction context currently associated with the service context handle is initialized at the end of the call if the flags parameter specifies that a new transaction should be started.
The XID of the transaction is set as an attribute of the transaction handle (OCI_ATTR_XID)
The following examples demonstrate the use of OCI transactional calls for manipulating global transactions.
This example shows a single session operating on different branches. This concept is illustrated by Figure 7-2, "Session Operating on Multiple Branches" .
int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; OCISession *usrhp; OCIStmt *stmthp1, *stmthp2; OCITrans *txnhp1, *txnhp2; dvoid *tmp; XID gxid; text sqlstmt[128]; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 0, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp1, OCI_HTYPE_STMT, 0, 0); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp2, OCI_HTYPE_STMT, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)srvhp, 0, OCI_ATTR_SERVER, errhp); /* set the external name and internal name in server handle */ OCIAttrSet((dvoid *)srvhp, OCI_HTYPE_SERVER, (dvoid *) "demo", 0, OCI_ATTR_EXTERNAL_NAME, errhp); OCIAttrSet((dvoid *)srvhp, OCI_HTYPE_SERVER, (dvoid *) "txn demo", 0, OCI_ATTR_INTERNAL_NAME, errhp); /* allocate a user context handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&usrhp, (ub4) OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"scott", (ub4)strlen("scott"), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"tiger", (ub4)strlen("tiger"),OCI_ATTR_PASSWORD, errhp); OCISessionBegin (svchp, errhp, usrhp, OCI_CRED_RDBMS, 0); OCIAttrSet((dvoid *)svchp, (ub4)OCI_HTYPE_SVCCTX, (dvoid *)usrhp, (ub4)0, OCI_ATTR_SESSION, errhp); /* allocate transaction handle 1 and set it in the service handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&txnhp1, OCI_HTYPE_TRANS, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp1, 0, OCI_ATTR_TRANS, errhp); /* start a transaction with global transaction id = [1000, 123, 1] */ gxid.formatID = 1000; /* format id = 1000 */ gxid.gtrid_length = 3; /* gtrid = 123 */ gxid.data[0] = 1; gxid.data[1] = 2; gxid.data[2] = 3; gxid.bqual_length = 1; /* bqual = 1 */ gxid.data[3] = 1; OCIAttrSet((dvoid *)txnhp1, OCI_HTYPE_TRANS, (dvoid *)&gxid, sizeof(XID), OCI_ATTR_XID, errhp); /* start global transaction 1 with 60 second time to live when detached */ OCITransStart(svchp, errhp, 60, OCI_TRANS_NEW); /* update scott.emp empno=7902, increment salary */ sprintf((char *)sqlstmt, "UPDATE EMP SET SAL = SAL + 1 WHERE EMPNO = 7902"); OCIStmtPrepare(stmthp1, errhp, sqlstmt, strlen(sqlstmt), OCI_NTV_SYNTAX, 0); OCIStmtExecute(svchp, stmthp1, errhp, 1, 0, 0, 0, 0); /* detach the transaction */ OCITransDetach(svchp, errhp, 0); /* allocate transaction handle 2 and set it in the service handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&txnhp2, OCI_HTYPE_TRANS, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp2, 0, OCI_ATTR_TRANS, errhp); /* start a transaction with global transaction id = [1000, 124, 1] */ gxid.formatID = 1000; /* format id = 1000 */ gxid.gtrid_length = 3; /* gtrid = 124 */ gxid.data[0] = 1; gxid.data[1] = 2; gxid.data[2] = 4; gxid.bqual_length = 1; /* bqual = 1 */ gxid.data[3] = 1; OCIAttrSet((dvoid *)txnhp2, OCI_HTYPE_TRANS, (dvoid *)&gxid, sizeof(XID), OCI_ATTR_XID, errhp); /* start global transaction 2 with 90 second time to live when detached */ OCITransStart(svchp, errhp, 90, OCI_TRANS_NEW); /* update scott.emp empno=7934, increment salary */ sprintf((char *)sqlstmt, "UPDATE EMP SET SAL = SAL + 1 WHERE EMPNO = 7934"); OCIStmtPrepare(stmthp2, errhp, sqlstmt, strlen(sqlstmt), OCI_NTV_SYNTAX, 0); OCIStmtExecute(svchp, stmthp2, errhp, 1, 0, 0, 0, 0); /* detach the transaction */ OCITransDetach(svchp, errhp, 0); /* Resume transaction 1, increment salary and commit it */ /* Set transaction handle 1 into the service handle */ OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp1, 0, OCI_ATTR_TRANS, errhp); /* attach to transaction 1, wait for 10 seconds if the transaction is busy */ /* The wait is clearly not required in this example because no other */ /* process/thread is using the transaction. It is only for illustration */ OCITransStart(svchp, errhp, 10, OCI_TRANS_RESUME); OCIStmtExecute(svchp, stmthp1, errhp, 1, 0, 0, 0, 0); OCITransCommit(svchp, errhp, (ub4) 0); /* attach to transaction 2 and commit it */ /* set transaction handle2 into the service handle */ OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp2, 0, OCI_ATTR_TRANS, errhp); OCITransCommit(svchp, errhp, (ub4) 0); } Example 2
This example demonstrates a single session operating on multiple branches that share the same transaction.
int main() { OCIEnv *envhp; OCIServer *srvhp; OCIError *errhp; OCISvcCtx *svchp; OCISession *usrhp; OCIStmt *stmthp; OCITrans *txnhp1, *txnhp2; dvoid *tmp; XID gxid; text sqlstmt[128]; OCIInitialize((ub4) OCI_OBJECT, (dvoid *)0, (dvoid * (*)()) 0, (dvoid * (*)()) 0, (void (*)()) 0 ); OCIHandleAlloc( (dvoid *) NULL, (dvoid **) &envhp, (ub4) OCI_HTYPE_ENV, 0, (dvoid **) &tmp); OCIEnvInit( &envhp, (ub4) OCI_DEFAULT, 21, (dvoid **) &tmp ); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &errhp, (ub4) OCI_HTYPE_ERROR, 52, (dvoid **) &tmp); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &srvhp, (ub4) OCI_HTYPE_SERVER, 52, (dvoid **) &tmp); OCIServerAttach( srvhp, errhp, (text *) 0, (sb4) 0, (ub4) OCI_DEFAULT); OCIHandleAlloc( (dvoid *) envhp, (dvoid **) &svchp, (ub4) OCI_HTYPE_SVCCTX, 52, (dvoid **) &tmp); OCIHandleAlloc((dvoid *)envhp, (dvoid **)&stmthp, OCI_HTYPE_STMT, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)srvhp, 0, OCI_ATTR_SERVER, errhp); /* set the external name and internal name in server handle */ OCIAttrSet((dvoid *)srvhp, OCI_HTYPE_SERVER, (dvoid *) "demo", 0, OCI_ATTR_EXTERNAL_NAME, errhp); OCIAttrSet((dvoid *)srvhp, OCI_HTYPE_SERVER, (dvoid *) "txn demo2", 0, OCI_ATTR_INTERNAL_NAME, errhp); /* allocate a user context handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&usrhp, (ub4) OCI_HTYPE_SESSION, (size_t) 0, (dvoid **) 0); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"scott", (ub4)strlen("scott"), OCI_ATTR_USERNAME, errhp); OCIAttrSet((dvoid *)usrhp, (ub4)OCI_HTYPE_SESSION, (dvoid *)"tiger", (ub4)strlen("tiger"),OCI_ATTR_PASSWORD, errhp); OCISessionBegin (svchp, errhp, usrhp, OCI_CRED_RDBMS, 0); OCIAttrSet((dvoid *)svchp, (ub4)OCI_HTYPE_SVCCTX, (dvoid *)usrhp, (ub4)0, OCI_ATTR_SESSION, errhp); /* allocate transaction handle 1 and set it in the service handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&txnhp1, OCI_HTYPE_TRANS, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp1, 0, OCI_ATTR_TRANS, errhp); /* start a transaction with global transaction id = [1000, 123, 1] */ gxid.formatID = 1000; /* format id = 1000 */ gxid.gtrid_length = 3; /* gtrid = 123 */ gxid.data[0] = 1; gxid.data[1] = 2; gxid.data[2] = 3; gxid.bqual_length = 1; /* bqual = 1 */ gxid.data[3] = 1; OCIAttrSet((dvoid *)txnhp1, OCI_HTYPE_TRANS, (dvoid *)&gxid, sizeof(XID), OCI_ATTR_XID, errhp); /* start global transaction 1 with 60 second time to live when detached */ OCITransStart(svchp, errhp, 60, OCI_TRANS_NEW); /* update scott.emp empno=7902, increment salary */ sprintf((char *)sqlstmt, "UPDATE EMP SET SAL = SAL + 1 WHERE EMPNO = 7902"); OCIStmtPrepare(stmthp, errhp, sqlstmt, strlen(sqlstmt), OCI_NTV_SYNTAX, 0); OCIStmtExecute(svchp, stmthp, errhp, 1, 0, 0, 0, 0); /* detach the transaction */ OCITransDetach(svchp, errhp, 0); /* allocate transaction handle 2 and set it in the service handle */ OCIHandleAlloc((dvoid *)envhp, (dvoid **)&txnhp2, OCI_HTYPE_TRANS, 0, 0); OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp2, 0, OCI_ATTR_TRANS, errhp); /* start a transaction with global transaction id = [1000, 123, 2] */ /* The global transaction will be tightly coupled with earlier transaction */ /* There is not much practical value in doing this but the example */ /* illustrates the use of tightly-coupled transaction branches */ /* In a practical case the second transaction that tightly couples with */ /* the first can be executed from a different process/thread */ gxid.formatID = 1000; /* format id = 1000 */ gxid.gtrid_length = 3; /* gtrid = 123 */ gxid.data[0] = 1; gxid.data[1] = 2; gxid.data[2] = 3; gxid.bqual_length = 1; /* bqual = 2 */ gxid.data[3] = 2; OCIAttrSet((dvoid *)txnhp2, OCI_HTYPE_TRANS, (dvoid *)&gxid, sizeof(XID), OCI_ATTR_XID, errhp); /* start global transaction 2 with 90 second time to live when detached */ OCITransStart(svchp, errhp, 90, OCI_TRANS_NEW); /* update scott.emp empno=7902, increment salary */ /* This is possible even if the earlier transaction has locked this row */ /* because the two global transactions are tightly coupled */ OCIStmtExecute(svchp, stmthp, errhp, 1, 0, 0, 0, 0); /* detach the transaction */ OCITransDetach(svchp, errhp, 0); /* Resume transaction 1 and prepare it. This will return */ /* OCI_SUCCESS_WITH_INFO because all branches except the last branch */ /* are treated as read-only transactions for tightly-coupled transactions */ OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp1, 0, OCI_ATTR_TRANS, errhp); if (OCITransPrepare(svchp, errhp, (ub4) 0) == OCI_SUCCESS_WITH_INFO) { text errbuf[512]; ub4 buflen; sb4 errcode; OCIErrorGet ((dvoid *) errhp, (ub4) 1, (text *) NULL, &errcode, errbuf, (ub4) sizeof(errbuf), (ub4) OCI_HTYPE_ERROR); printf("OCITransPrepare - %s\n", errbuf); } /* attach to transaction 2 and commit it */ /* set transaction handle2 into the service handle */ OCIAttrSet((dvoid *)svchp, OCI_HTYPE_SVCCTX, (dvoid *)txnhp2, 0, OCI_ATTR_TRANS, errhp); OCITransCommit(svchp, errhp, (ub4) 0); }
