SQLSetStmtAttr()--Set Transaction Isolation Level
The ODBC Driver supports all transaction isolation levels available in the ODBC specification, including:
• Serializable
• Read committed
• Read uncommitted
• Repeatable read
The above isolation levels are specified by the ODBC attributes SQL_ATTR_TXN_SERIALIZABLE, SQL_ATTR_TXN_READ_COMMITTED, SQL_TXN, READ_UNCOMMITTED, and SQL_TXN_REPEATABLE_READ, respectively. Transaction isolation is specified by SQLSetStmtAttr() function via the SQL_ATTR_TXN_ISOLATION connection attribute. The SQLGetStmtAttr() function returns the current isolation level when the SQL_ATTR_TXN_ISOLATION option is specified.
Other types of transaction isolation supported by Ingres, such as system, are not available in SQLSetStmtAttr(). Use SQLExecDirect() to execute the SET command directly in such cases. This is also the case when locking is specified with the SET LOCKMODE command, such as for row-level locking.