Question

我有以下T-SQL：

USE [MYDB]
GO
SET XACT_ABORT, NOCOUNT ON
GO
BEGIN TRANSACTION;
BEGIN TRY
        ALTER TABLE [dbo].[ContactRole] 
        DROP CONSTRAINT [FK_8bff7074914bc29885004c0a323] 
        GO
END TRY
BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine ,ERROR_MESSAGE() AS ErrorMessage;

    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH

IF @@TRANCOUNT > 0
    COMMIT TRANSACTION;

解析后会出现此错误：

Msg 102，Level 15，State 1，Line 9
'FK_8bff7074914bc29885004c0a323'附近的语法不正确。

单独或仅在事务中时，没有解析错误。

Answer 1

在GO行

之后删除ALTER TABLE ... DROP CONSTRAINT ..

....
BEGIN TRANSACTION;
BEGIN TRY
    ALTER TABLE [dbo].[ContactRole] 
    DROP CONSTRAINT [FK_8bff7074914bc29885004c0a323] 

    COMMIT TRANSACTION;
END TRY
BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine ,ERROR_MESSAGE() AS ErrorMessage;

    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH

GO 不是一个SQL关键字 - 它只被SQL Server Management Studio理解为“批处理分隔符”。

另外：将COMMIT TRANSACTION语句放在ALTER TABLE命令之后 - 毕竟，如果出现问题 - 代码执行将立即跳转到catch块，这样只执行该行如果一切顺利

Answer 2

你不应该拥有Go，因为它表示批次的结束，你的提交应该在alter table之后。

此外，没有必要检查一个事务是否在catch上运行，因为在这种情况下，它总是有

USE [MYDB]
GO
SET XACT_ABORT, NOCOUNT ON
GO
BEGIN TRANSACTION;
BEGIN TRY
        ALTER TABLE [dbo].[ContactRole] 
        DROP CONSTRAINT [FK_8bff7074914bc29885004c0a323] 

        COMMIT TRANSACTION; 
END TRY
BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine ,ERROR_MESSAGE() AS ErrorMessage;

        ROLLBACK TRANSACTION;
END CATCH

在TRY / CATCH中使用DROP CONSTRAINT的语法错误

2 个答案: