ODBC Programming Considerations

ODBC Driver

The CONNX ODBC driver can be used successfully with off-the-shelf products and by those who wish to write applications that call the driver.

If you are planning to write applications that call ODBC drivers, refer to the Microsoft Open Database Connectivity Software Development Kit (ODBC SDK), Programmer's Reference, for additional technical information about the ODBC driver manager, the ODBC function calls, and ODBC technology concepts. The kit, ISBN #1572315164, is published by Microsoft Press, which can be reached at 1-800-677-7377.

Record Locking

Record locking in RMS, IBM DB2, CICS/VSAM, DBMS, and Oracle database tables is handled automatically based on the type of SQL statement sent to the SQL server. UPDATE and DELETE statements lock the record at the start of the action, and immediately release the lock when complete. SELECT statements do not lock records, but can still read locked records in RMS using the RMS GET REGARDLESS flag.

During the record-locking procedure, a READLOCK is put on all transactions going forward. The application gets the latest copy of the record and prevents other users from modifying the record. It then issues an update and a COMMIT command, after which it retrieves the most recently saved record to make sure it matches.

 

Related Topics

image\CHICLET.jpg DB2

image\CHICLET.jpg DataFlex

image\CHICLET.jpg RMS

image\CHICLET.jpg Oracle Rdb

image\CHICLET.jpg DBMS

image\CHICLET.jpg Oracle

image\CHICLET.jpg VSAM