Error Handling In Stored Procedures Sql
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Errors in SQL Server 2012 03 January 2013Handling Errors in SQL Server 2012The error handling of SQL Server has always been somewhat error handling in stored procedure sql server 2008 mysterious. Now at last, the THROW statement has been included in SQL Server
Error Handling In Stored Procedure Sql Server 2012
2012 that, combined with the TRY ... CATCH block, makes error handling far easier. Robert Sheldon explains all. 194 mysql stored procedure error handling 14 Robert Sheldon Since the release of SQL Server 2005, you've been able to handle errors in your T-SQL code by including a TRY…CATCH block that controls the flow of your script oracle stored procedure error handling should an error occur, similar to how procedural languages have traditionally handled errors. The TRY…CATCH block makes it easy to return or audit error-related data, as well as take other actions. And within the block-specifically, the CATCH portion-you've been able to include a RAISERROR statement in order to re-throw error-related data to the calling application. However, with the release of SQL Server 2012,
Sql Stored Procedure Try Catch
you now have a replacement for RAISERROR, the THROW statement, which makes it easier than ever to capture the error-related data. In this article, we'll look at the TRY…CATCH block used with both the RAISERROR and THROW statements. The examples are based on a table I created in the AdventureWorks2012 sample database, on a local instance of SQL Server 2012. Listing 1 shows the T-SQL script I used to create the LastYearSales table. 123456789101112131415161718 USE AdventureWorks2012;GOIF OBJECT_ID('LastYearSales', 'U') IS NOT NULLDROP TABLE LastYearSales;GOSELECTBusinessEntityID AS SalesPersonID,FirstName + ' ' + LastName AS FullName,SalesLastYearINTOLastYearSalesFROMSales.vSalesPersonWHERESalesLastYear > 0;GO Listing 1: Creating the LastYearSales table The script should be fairly straightforward. I use a SELECT…INTO statement to retrieve data from the Sales.vSalesPerson view and insert it into the newly created table. However, to demonstrate how to handle errors, we need to add one more element to our table: a check constraint that ensures the SalesLastYear value is never less than zero. Listing 2 shows the ALTERTABLE statement I used to add the constraint. 123 ALTER TABLE LastYearSalesADD CONSTRAINT ckSalesTotal CHECK (SalesLastYear >= 0);GO Listing 2: Adding a check constraint to the LastYearSales table
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 description of the idiosyncrasies with error handling in SQL sql trigger error handling Server and ADO. That article is in some sense part one in the series. However, you sql function error handling can read this article without reading the background article first, and if you are not a very experienced user of SQL Server, I
Sql Server Stored Procedure Error Handling Best Practices
recommend you to start here. In places there are links to the background article, if you want more information about a certain issue. Note: this article is aimed at SQL2000 and earlier versions of SQL Server. SQL2005 offers significantly improved https://www.simple-talk.com/sql/database-administration/handling-errors-in-sql-server-2012/ 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: 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 http://www.sommarskog.se/error-handling-II.html @@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 compromise the integrity of your data. Or it can cause a transaction to run for much longer time than intended, leading to blocking and risk that the user loses all his updates when he logs out. In the first section, I summarize the most important points of the material in the background article, so you know un
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss http://stackoverflow.com/questions/725891/what-is-the-best-practice-use-of-sql-server-t-sql-error-handling 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 error handling 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 error handling in 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(@