SQL Server 事务嵌套

示例代码：

DECLARE @TranCounter INT;



SET @TranCounter = @@TRANCOUNT;

IF @TranCounter > 0

    -- Procedure called when there is

    -- an active transaction.

    -- Create a savepoint to be able

    -- to roll back only the work done

    -- in the procedure if there is an

    -- error.

    SAVE TRANSACTION ProcedureSave;

ELSE

    -- Procedure must start its own

    -- transaction.

    BEGIN TRANSACTION;

-- Modify database.

BEGIN TRY



    /**

        Write your T-SQL here...

    **/



    -- Get here if no errors; must commit

    -- any transaction started in the

    -- procedure, but not commit a transaction

    -- started before the transaction was called.

    IF @TranCounter = 0

        -- @TranCounter = 0 means no transaction was

        -- started before the procedure was called.

        -- The procedure must commit the transaction

        -- it started.

        COMMIT TRANSACTION;

END TRY

BEGIN CATCH

    -- An error occurred; must determine

    -- which type of rollback will roll

    -- back only the work done in the

    -- procedure.

    IF @TranCounter = 0

        -- Transaction started in procedure.

        -- Roll back complete transaction.

        ROLLBACK TRANSACTION;

    ELSE

        -- Transaction started before procedure

        -- called, do not roll back modifications

        -- made before the procedure was called.

        IF XACT_STATE() <> -1

            -- If the transaction is still valid, just

            -- roll back to the savepoint set at the

            -- start of the stored procedure.

            ROLLBACK TRANSACTION ProcedureSave;

            -- If the transaction is uncommitable, a

            -- rollback to the savepoint is not allowed

            -- because the savepoint rollback writes to

            -- the log. Just return to the caller, which

            -- should roll back the outer transaction.



    -- After the appropriate rollback, echo error

    -- information to the caller.

    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