What are the best practices for using RAISERROR and THROW in stored procedures?

1 RAISERROR overview

RAISERROR is a legacy statement that allows you to generate a user-defined error message and return it to the caller. You can specify the error number, severity, state, message, and optional parameters. You can also use RAISERROR with the WITH LOG option to write the error message to the error log and the application log. RAISERROR can be used in any scope of a stored procedure, and it can be used to break the flow of a batch or a transaction.

2 THROW overview

THROW is a newer statement that was introduced in SQL Server 2012. It allows you to raise an exception and transfer the execution to a CATCH block of a TRY...CATCH construct. You can specify the error number, message, and state, but not the severity or the parameters. THROW can only be used in the CATCH block of a TRY...CATCH construct, and it can be used to re-throw the original error that occurred in the TRY block.

3 Comparing RAISERROR and THROW

There are some advantages and disadvantages of using RAISERROR and THROW in stored procedures. RAISERROR gives you more flexibility and control over the error message and the error handling logic, but it also requires more code and may not comply with the ANSI SQL standard. THROW gives you a simpler and cleaner way to raise an exception and propagate it to the caller, but it also has some limitations and restrictions on the error information and the scope of use.

5 Handling errors with TRY...CATCH

Regardless of whether you use RAISERROR or THROW, you should always use a TRY...CATCH construct to handle errors in your stored procedures. A TRY...CATCH construct allows you to separate the normal execution logic from the error handling logic, and to catch and handle any errors that occur in the TRY block. In the CATCH block, you can use RAISERROR or THROW to return the error information to the caller, or perform other actions such as rolling back a transaction, logging the error, or executing alternative logic.

6 Testing and debugging errors

Finally, you should always test and debug your stored procedures to ensure that they handle errors correctly and gracefully. You can use tools such as SQL Server Management Studio, SQL Server Profiler, or SQL Server Error Log to execute, trace, and monitor your stored procedures and the errors they generate. You can also use techniques such as adding breakpoints, print statements, or debug messages to your code to help you identify and fix any errors or bugs.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?