After an application program executes a SQL statement, it can examine a status code. This status code (or return code) indicates whether the statement executed successfully or failed and gives the reason for the failure. You can use the same mechanism to indicate the success or failure of a CALL statement to a procedure.
Error reporting uses either the SQLCODE or SQLSTATE status descriptions.
Whenever a SQL statement executes, a value appears in special procedure variables called SQLSTATE and SQLCODE. The special value indicates whether there were any unusual conditions encountered when the statement was executed. You can check the value of SQLSTATE or SQLCODE in an IF statement following a SQL statement, and take actions depending on whether the statement succeeded or failed.
For example, the SQLSTATE variable can be used to indicate if a row is successfully fetched. The TopCustomerValue procedure used the SQLSTATE test to detect that all rows of a SELECT statement had been processed.
Default handling of errors
Error handling with ON EXCEPTION RESUME
Default handling of warnings
Nested compound statements and exception handlers
Example: Creating an error logging procedure that can be called by an exception handler
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