SAVE TRANSACTION vs BEGIN TRANSACTION (SQL Server) how to nest transactions nicely

Question

I have a stored procedure that needs to set a save point so that it can, under certain circumstances, undo everything it did and return an error code to the caller, or accep

Answer 1

I have used this type of transaction manager in my Stored Procedures :

    CREATE PROCEDURE Ardi_Sample_Test  
        @InputCandidateID INT  
    AS  
        DECLARE @TranCounter INT;  
        SET @TranCounter = @@TRANCOUNT;  
        IF @TranCounter > 0  
            SAVE TRANSACTION ProcedureSave;  
        ELSE  
            BEGIN TRANSACTION;  
        BEGIN TRY  

            /*
            <Your Code>
            */

            IF @TranCounter = 0  
                COMMIT TRANSACTION;  
        END TRY  
        BEGIN CATCH  
            IF @TranCounter = 0  
                ROLLBACK TRANSACTION;  
            ELSE  
                IF XACT_STATE() <> -1  
                    ROLLBACK TRANSACTION ProcedureSave;  

            DECLARE @ErrorMessage NVARCHAR(4000);  
            DECLARE @ErrorSeverity INT;  
            DECLARE @ErrorState INT;  
            SELECT @ErrorMessage = ERROR_MESSAGE();  
            SELECT @ErrorSeverity = ERROR_SEVERITY();  
            SELECT @ErrorState = ERROR_STATE();  

            RAISERROR (@ErrorMessage, @ErrorSeverity, @ErrorState);  
        END CATCH  
    GO  

Answer 2

Extending Brian B's answer.

This ensures the save point name is unique and uses the new TRY/CATCH/THROW features of SQL Server 2012.

DECLARE @mark CHAR(32) = replace(newid(), '-', '');
DECLARE @trans INT = @@TRANCOUNT;

IF @trans = 0
    BEGIN TRANSACTION @mark;
ELSE
    SAVE TRANSACTION @mark;

BEGIN TRY
    -- do work here

    IF @trans = 0
        COMMIT TRANSACTION @mark;
END TRY
BEGIN CATCH
    IF xact_state() = 1 OR (@trans = 0 AND xact_state() <> 0) ROLLBACK TRANSACTION @mark;
    THROW;
END CATCH

Answer 3

I believe I've figured this all out now, so I will answer my own question...

I've even blogged my findings if you want more details at http://geekswithblogs.net/bbiales/archive/2012/03/15/how-to-nest-transactions-nicely---quotbegin-transactionquot-vs-quotsave.aspx

So my SP starts with something like this, to start a new transaction if there is none, but use a Save Point if one is already in progress:

DECLARE @startingTranCount int
SET @startingTranCount = @@TRANCOUNT

IF @startingTranCount > 0
    SAVE TRANSACTION mySavePointName
ELSE
    BEGIN TRANSACTION
-- …

Then, when ready to commit the changes, you only need to commit if we started the transaction ourselves:

IF @startingTranCount = 0
    COMMIT TRANSACTION

And finally, to roll back just your changes so far:

-- Roll back changes...
IF @startingTranCount > 0
    ROLLBACK TRANSACTION MySavePointName
ELSE
    ROLLBACK TRANSACTION