SQL Server存储过程事务

DECLARE @TRANCOUNT INT --用于判断是否为子事务，使commit,rollback只控制本存储过程  
SET @TRANCOUNT = @@TRANCOUNT  
---------定义错误信息-----------------------          
DECLARE @ErrorMessage NVARCHAR(4000)    --错误消息
        ,@ErrorSeverity INT             --错误级别
        ,@ErrorState INT                --错误状态
----------开启事务-------------------------------------------
IF @TRANCOUNT=0 
    BEGIN TRAN QCSELECT
ELSE  
    SAVE TRAN QCSELECT  
BEGIN TRY
    --此处写处理逻辑
    IF @TRANCOUNT=0
        COMMIT TRAN QCSELECT
END TRY
BEGIN CATCH
    ROLLBACK TRAN QCSELECT
    SELECT @ErrorMessage = ERROR_MESSAGE(),@ErrorSeverity = ERROR_SEVERITY(),@ErrorState = ERROR_STATE()
    RAISERROR (@ErrorMessage,@ErrorSeverity,@ErrorState)
END CATCH