Overview

Errors encountered while accessing the database, or involving queue or scratch activity are handled differently depending on whether or not SQL commands are used.

SQL Commands

When CA IDMS/DB executes an SQL statement, it returns information about the status of statement execution to a data structure called the SQLCA. The dialog contains logical to handle exceptional conditions resulting from statement execution. This logic takes the form of checking SQLCA information through the use of a conditional statement or through the use of the WHENEVER SQLERROR or WHENEVER SQLWARNING statement. In either situation, control is always returned to the dialog.

Note: For more information about conditional statements and the WHENEVER SQLERROR statement processed during an SQL session, see the CA IDMS SQL Programming Guide.

Non-SQL Commands

When CA IDMS/DB executes a non-SQL process command that involves database, queue, or scratch activity, or a WRITE PRINTER utility command, CA ADS returns a 4-byte status code to an internal error-status field for the issuing dialog. A subsequent process command statement can test for the presence of a specified status code. Based on the outcome of the test, further processing can be done.

Handling errors in the non-SQL environment involves the use of the following:

The autostatus facility, which handles errors generated by command processing
Error expressions, which specify allowable status codes that can be returned
The status definition record, which allows level-88 condition names to be associated with status codes

The autostatus facility, error expressions, and the status definition record are discussed separately in this section.

Note: For more information about using automatic editing and error-handling facilities to evaluate input data, see the CA IDMS Mapping Facility Guide.