The WHENEVER statement must appear before the SQL statements you want to 

affect. Otherwise, the precompiler does not know that additional error handling 

code should be generated for the executable SQL statements. You can have any 

combination of the three basic forms active at any time. The order in which you 

declare the three forms is not significant.

To avoid an infinite looping situation, ensure that you undo the WHENEVER 

handling before any SQL statements are executed inside the handler. You can do 

this using the WHENEVER SQLERROR CONTINUE statement.

Declaring the SQLCA for error handling

You can declare the SQLCA in your application program so that the database 

manager can return information to your application. When you preprocess your 

program, the database manager inserts host language variable declarations in 

place of the INCLUDE SQLCA statement. The system communicates with your 

program using the variables for warning flags, error codes, and diagnostic 

information.

After executing each SQL statement, the system returns a return code in both 

SQLCODE and SQLSTATE. SQLCODE is an integer value that summarizes the 

execution of the statement, and SQLSTATE is a character field that provides 

common error codes across IBM's relational database products. SQLSTATE 

also conforms to the ISO/ANS SQL92 and FIPS 127 2 standard.

Note that if SQLCODE is less than 0, it means an error has occurred and the 

statement has not been processed. If the SQLCODE is greater than 0, it means a 

warning has been issued, but the statement is still processed.

For a DB2 application written in C or C++, if the application is made up of multiple 

source files, only one of the files should include the EXEC SQL INCLUDE 

SQLCA statement to avoid multiple definitions of the SQLCA. The remaining 

source files should use the following lines:

#include "sqlca.h"

extern struct sqlca sqlca;

Condition handling in DB2 stored procedure

Although the content of this book is based on MySQL Version 4, and stored 

procedure support is advertised for Version 5 of MySQL, it seems appropriate to 

include a few examples of DB2 condition handling. For detailed information on 

condition handlers you may refer to DB2 UDB manual 

Application Development 

Guide: Programming Server Applications, 

SC09 4827.

The general form of a handler declaration is:

   DECLARE     + CONTINUE +     HANDLER   FOR   condition      >

 Chapter 7. Application porting 

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