Exception handling is a mechanism to capture the application error, and process it conditionally. While writing SQL-stored procedures, one can write without any error-handling mechanism in place. In this case, if there is any runtime error, the execution stops and the procedure will terminate. In earlier versions of DB2, the basic error checking was mainly using SQLCODE and SQLSTATE values of the DB2 communication area.
Along with earlier exception handlers, DB2 9.7 supports most of Oracle PL/SQL exception handlers, such as defining exception blocks, customized exception-handler declaration, and raising custom-defined errors.
DB2 9.7 supports almost all the Oracle pre-defined exceptions, such as NO_DATA_FOUND, TOO_MANY_ROWS, INVALID_CURSOR, ZERO_DIVIDE, DUP_VAL_ON_INDEX, VALUE_ERROR, and many more in the list. Now we will look at the way in which one can raise a customized application error.