Sybase 12.4.2 manual Error handling with on Exception Resume, 258

Errors and warnings in procedures

Error handling with ON EXCEPTION RESUME

If the ON EXCEPTION RESUME clause is included in the CREATE PROCEDURE statement, the procedure checks the following statement when an error occurs. If the statement handles the error, then the procedure does not return control to the calling environment when an error occurs. Instead, it continues executing, resuming at the statement after the one causing the error.

Note When a statement has several parts or clauses, such as IF, ELSE IF, END IF, or FOR and END FOR, the “following statement” refers to the next new statement, not a statement part.

The following statements are considered error-handling statements:

•IF

•SELECT @variable =

•CASE

•LOOP

•LEAVE

•CONTINUE

•CALL

•EXECUTE

•SIGNAL

•RESIGNAL

•DECLARE

The following example illustrates how this works.

Drop the procedures Remember to drop both the InnerProc and OuterProc procedures before continuing with the tutorial. You can do this by entering the following commands in the command window:

DROP PROCEDURE OUTERPROC;

DROP PROCEDURE INNERPROC

The following demonstration procedures show what happens when an application calls the procedure OuterProc; and OuterProc in turn calls the procedure InnerProc, which then encounters an error. These demonstration procedures are based on those used earlier in this section:

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