Default Values

From SQL PL Guide for DB2

Stored procedures in DB2 does not support default values in DB2 9 and DB2 9.5. But there's a workaround available to specify default values: The input parameters must be test for NULL at the beginning of the procedure, output parameters must be checked before the procedure ends.

Example DB2 9 and DB2 9.5:

 CREATE PROCEDURE myproc (IN var01 INTEGER, OUT var02 INTEGER)
 BEGIN
    IF (p1 is null) THEN
       SET var01 = 0;
    END IF;

   ... code ...

    IF (p2 is null) THEN
       SET var02 = 0;
    END IF;

 END

Since DB2 9.7 an Default Option is available.

Example DB2 9.7:

 CREATE PROCEDURE myproc (IN var01 INTEGER DEFAULT 0, OUT var02 INTEGER DEFAULT 0)
 BEGIN

   ... code ...
 
 END