Nov 26, 2014

TRY/CATCH and error handling in SQL server 2005/2008

SQL Server 2005 provide a strong set of tool to handle error or exception, in privious version it was not easy to handle exceptions.
We use TRY/CATCH in SQL Server same as populer languages, We write saperate logic and exception handling code.

Syntax:
BEGIN TRY
-- Your Code or query
END TRY
BEGIN CATCH
-- Handling code
END CATCH

We write our logic code within TRY bolck and exception code in CATCH block, if nay error occur in logic code it jumps to CATCH 

block, resume the execution and transaction is rollback.

Functions which is use in CATCH

1- ERROR_NUMBER() Returns error no othe error message.
2- ERROR_SEVERITY() returns the error severity regardless of how many times it is run.
3- ERROR_STATE() Returns the state number of error messages that cause the catch block.
4- ERROR_PROCEDURE() Return the Procedure Name.
5- ERROR_LINE() Return error line number.
6- ERROR_MESSAGE() return error description.

Note : If we are calling all above method out side from CATCH block it will return NULL..

Example


CREATE PROCEDURE dbo.usp_TRY_CATCH_TEST
AS
BEGIN
BEGIN TRY
   SELECT 1/0
END TRY
BEGIN CATCH
   SELECT ERROR_NUMBER() AS error_no
   ,ERROR_SEVERITY() AS error_severity
   ,ERROR_STATE() AS error_state
   ,ERROR_PROCEDURE() AS error_procedure
   ,ERROR_LINE() AS error_lineNo
   ,ERROR_MESSAGE() AS error_message
END CATCH
END