Error Checking In Sql Server
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how you should implement error handling when you write stored procedures, including when you call them from ADO. The other article, Error Handling in SQL Server - a Background, gives a deeper http://www.sommarskog.se/error-handling-II.html description of the idiosyncrasies with error handling in SQL Server and ADO. That http://stackoverflow.com/questions/725891/what-is-the-best-practice-use-of-sql-server-t-sql-error-handling article is in some sense part one in the series. However, you can read this article without reading the background article first, and if you are not a very experienced user of SQL Server, I recommend you to start here. In places there are links to the background article, if you want more information about a sql server certain issue. Note: this article is aimed at SQL2000 and earlier versions of SQL Server. SQL2005 offers significantly improved methods for error handling with TRY-CATCH. This article is not apt if you are using SQL 2005 or later. I don't have a complete article on error handling for SQL 2005, but I have an unfinished article with a section Jumpstart Error Handling that still can be useful. Table of Contents: in sql server Introduction The Presumptions A General Example Checking Calls to Stored Procedures The Philosophy of Error Handling General Requirements Why Do We Check for Errors? When Should You Check @@error? ROLLBACK or not to ROLLBACK - That's the Question SET XACT_ABORT ON revisited Error Handling with Cursors Error Handling with Triggers Error Handling with User-Defined Functions Error Handling with Dynamic SQL Error Handling in Client Code What to Do in Case of an Error? Command Timeouts Why is My Error Not Raised? Getting the Return Value from a Stored Procedure Acknowledgements and Feedback Revision History Introduction Error handling in stored procedures is a very tedious task, because T-SQL offers no exception mechanism, or any On Error Goto. All you have is the global variable @@error which you need to check after each statement for a non-zero value to be perfectly safe. If you call a stored procedure, you also need to check the return value from the procedure. In fact, this is so extremely tedious, so you will find that you will have to make compromises and in some situations assume that nothing can go wrong. Still, you cannot just ignore checking for errors, because ignoring an error could cause your updates to be incomplete, and compromis
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up What is the best practice use of SQL Server T-SQL error handling? up vote 20 down vote favorite 12 We have a large application mainly written in SQL Server 7.0, where all database calls are to stored procedures. We are now running SQL Server 2005, which offers more T-SQL features. After just about every SELECT, INSERT, UPDATE, and DELETE, the @@ROWCOUNT and @@ERROR get captured into local variables and evaluated for problems. If there is a problem the following is done: error message output parameter is set rollback (if necessary) is done info is written (INSERT) to log table return with a error number, unique to this procedure (positive if fatal, negative is warning) They all don't check the rows (only when it is known) and some differ with more or less log/debug info. Also, the rows logic is somethimes split from the error logic (on updates where a concurrency field is checked in the WHERE clause, rows=0 means someone else has updated the data). However, here is a fairly generic example: SELECT, INSERT, UPDATE, or DELETE SELECT @Error=@@ERROR, @Rows=@@ROWCOUNT IF @Rows!=1 OR @Error!=0 BEGIN SET @ErrorMsg='ERROR 20, ' + ISNULL(OBJECT_NAME(@@PROCID), 'unknown') + ' - unable to ???????? the ????.' IF @@TRANCOUNT >0 BEGIN ROLLBACK END SET @LogInfo=ISNULL(@LogInfo,'')+'; '+ISNULL(@ErrorMsg,'')+ + ' @YYYYY=' +dbo.FormatString(@YYYYY) +', @XXXXX=' +dbo.FormatString(@XXXXX) +', Error=' +dbo.FormatString(@Error) +', Rows=' +dbo.FormatString(@Rows) INSERT INTO MyLogTable (...,Message) VALUES (....,@LogInfo) RETURN 20 END I am looking into replacing how we do this with the TRY-CATCH T-SQL. I've read about the TRY...CATCH (Transact-SQL) syntax, so don't just post some summary of that. I'm looking for any good ideas and how best to do or improve our error handling methods. It doesn't have to be Try-Catch, just any good or best practice use of T-SQL error handling. sql-serve