int odbc_num_rows (int result_id)
odbc_num_rows() will return the number of rows in an ODBC result. This function will return -1 on error. For INSERT, UPDATE and DELETE statements odbc_num_rows() returns the number of rows affected. For a SELECT clause this can be the number of rows available.
Note: Using odbc_num_rows() to determine the number of rows available after a SELECT will return -1 with many drivers.