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Asked: 2024-09-25T14:37:03+05:30 In:

How can I retrieve the list of columns returned by a stored procedure in SQL Server?

I’ve been diving into SQL Server recently and hit a bit of a roadblock that I could use your help with. I’ve got this stored procedure that’s set up to return a dataset, but I’m completely lost when it comes to figuring out what columns are actually part of that result. I mean, I can execute the procedure and see the data, but ideally, I want to know in advance what columns I’ll be dealing with.

I tried a couple of things, like checking the documentation (if it even exists) or looking in the database for any comments or definitions, but nothing seems to show me a clear picture. This is crucial for me since I need to build some dynamic SQL queries later, and I want to ensure that I’m referencing the right column names.

I’ve heard some people talk about using system stored procedures, like `sp_help` or querying the system views, but I’m not sure how to go about it. Does anyone have experience with this? It feels like I’m missing a simple solution, but I’m not sure what steps to take next.

I’ve also read about some newer features in SQL Server that could help out, but I’m not quite sure if they apply here. Has anyone stumbled upon a definitive method that works consistently? I’d love to hear how you’ve handled this.

Another thing is that I’m a bit concerned about performance. I don’t want to slow things down by querying system tables too much. Is there a way to do it efficiently without impacting the database performance?

Any tips, tricks, or snippets of code you could share would be super helpful! Really eager to learn how to get this column list without too much fuss. Thanks in advance for any guidance you can provide!

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    2 Answers

    1. If you’re looking to determine the output columns of a stored procedure in SQL Server, one effective approach is to use the `sp_describe_first_result_set` system stored procedure. This system procedure will allow you to obtain metadata about the result set that is returned by your stored procedure. You can simply execute it with your stored procedure name as the parameter like this: EXEC sp_describe_first_result_set 'EXEC dbo.YourStoredProcedureName', NULL, 0;. This command will give you information about the column names, data types, and other properties without actually running the procedure. This way, you can query the necessary details for your dynamic SQL queries while minimizing the impact on performance.

      In addition to `sp_describe_first_result_set`, you can also query the `sys.dm_exec_describe_first_result_set` dynamic management function, which operates similarly and provides you with the schema of the result set in a more dynamic manner. It’s worth noting that these methods are generally efficient, as they do not execute the procedure but simply read the metadata from the SQL Server’s internal structures. Since you’re concerned about performance, be mindful to use these methods sparingly and when necessary. With learning and frequent use, these tools can greatly enhance your ability to work with stored procedures and dynamic SQL efficiently.



    2. Help with SQL Server Stored Procedures

      Finding Out Columns from a Stored Procedure

      Ok, so I totally feel your pain! When it comes to figuring out what columns a stored procedure returns, things can get a bit tricky. Here are a few things you could try:

      1. Using sp_help

      You can use the system stored procedure sp_help to get general information about the stored procedure. Just run:

      EXEC sp_help 'YourProcedureName'

      This should show you the columns and their data types, but sometimes it might not give you the exact return set, so proceed to the next step if needed!

      2. Querying Information Schema Views

      You can also check the INFORMATION_SCHEMA views. Running a query like the following can help:

      SELECT * FROM INFORMATION_SCHEMA.COLUMNS 
WHERE TABLE_NAME = 'YourTableName'

      This returns columns for a specific table and might give you an idea if the stored procedure is selecting from that table.

      3. SET FMTONLY ON

      This is a bit of an advanced technique, but you can use SET FMTONLY ON to get the metadata of what columns are returned by your procedure without actually executing the entire procedure:

      SET FMTONLY ON;
EXEC YourProcedureName;
SET FMTONLY OFF;

      Be careful, as this feature can sometimes be a little quirky depending on the SQL Server version!

      4. Dynamic SQL

      If you need to build dynamic queries later, make sure to store the column names in a variable after figuring them out with one of the above methods. This way, you’re not hardcoding names!

      5. Performance Concerns

      Definitely get it about performance! Just be mindful of not running these inquiries too often. It’s generally fine to check system tables or views occasionally; just don’t do it in a tight loop or during peak times.

      6. Newer SQL Server Features

      Some newer SQL Server installations might also have features like sys.dm_exec_describe_first_result_set which can retrieve metadata without running the procedure:

      EXEC sp_describe_first_result_set N'EXEC YourProcedureName', NULL, 0;

      Super handy if available!

      In the end, it’s totally a learning curve, and you’ll get the hang of it! Good luck, and don’t hesitate to ask for more help if you’re stuck!


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