How to return the output of a stored procedure into a variable in SQL Server

Grasping output parameters

For carrying away multiple values or a non-integer result from a stored procedure, you need to gear up with OUTPUT parameters. Here's a step-by-step guide to get you there:

Declaring OUTPUT parameters

Kick-off by declaring your variables with the same data types as those of the output parameters of your stored procedure. No mix-matching allowed here!

Calling stored procedure with OUTPUT

Invoke the stored procedure ensuring your recently declared variables and OUTPUT parameters are locked and linked.

Safeguarding OUTPUTs into local variables

Once the procedure is executed successfully, your variables become the custodians of the result, ready for further execution in queries or conditional logics.

Mind the compatibility with your SQL Server version when using certain features.

Transferring multiple return values and result sets

Quite often, a single pebble doesn't make much noise. You might need a bunch of them or they might be carrying some hefty data. Here's how you handle such scenarios:

Using temp tables with result sets

When you expect a result set, you can use a temp table as a wheelbarrow to carry the output of a stored procedure:

CREATE TABLE #TempTable (Column1 INT, Column2 VARCHAR(100)) -- Makes sense, right?
INSERT INTO #TempTable
EXEC YourStoredProcedure
-- Whoosh... Here goes the procedure output into temp table!
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Scooping data out of temp tables

Once the data lands there, you can select from the temp table to process it as you please.

SELECT * FROM #TempTable
-- Round up the usual suspects!
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On a diet and need just a single value? No problem, just use SELECT TOP 1.

Exploiting the Insert EXEC statement

One less trodden path, but worth exploring if you wish to capture a result set directly without performing any circus tricks is the INSERT EXEC statement. Ensure your table and the result set don't play hide and seek with the structure.

INSERT INTO YourTable EXEC YourStoredProcedure
-- It's like riding the elevator directly to the penthouse!
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Follow the best practices and handle unexpected situations

Implementing error handling, just like your morning cuppa, is crucial for setting up the day within stored procedures. Here's how you can sip it right:

Check with @@rowcount

Verify the number of rows that were swept away by the stored procedure. No row affected? Houston, we have a problem!

IF @@ROWCOUNT = 0
    RAISEERROR('No rows affected', 16, 1)  -- Not a single row, are we playing hide and seek?
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Catch and release errors

Use TRY...CATCH blocks to trap and re-release the errors with unmatched grace:

BEGIN TRY
    EXEC YourStoredProcedure  -- Go forth, brave procedure!
END TRY
BEGIN CATCH
    -- Uh-oh, send in the dragons!
END CATCH
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Direct returns

For procedures that return a single integer value, use RETURN and capture the value post execution, much like capturing a Twitter bird flying around worldwide:

DECLARE @ReturnValue INT
EXEC @ReturnValue = YourStoredProcedure
IF @ReturnValue = ExpectedValue  -- Our little bird has arrived!
    -- Proceed with logic
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