Question

如果SELECT中的语句存在，则应该回滚触发器。问题是，事实并非如此。当我只从触发器运行SELECT时，它显示存在一行。但是当我尝试使用与触发器中硬编码相同的值的DELETE时，触发器会触发但不会执行回滚。任何人有任何想法可能是错的？

CREATE TRIGGER trg_del ON Projektbefattningar

FOR DELETE
AS

  SELECT @befNr = Befattningsnr, @pNr = pNr, @EtappNr = Etappnr FROM deleted
-- Not currently using these. Using hard coded values to illustrate my problem

    IF EXISTS (
        SELECT *
        FROM projektbefattningar
        WHERE Befattningsnr = 2 AND pNr = 1 and Etappnr = 1 AND Anställningsnr is not null
        )
    BEGIN
        RAISERROR('Could not delete, Anställningsnr is not null', 16, 1)
        --THROW 50001, 'Could not delete, Anställningsnr is not null', 1;
        ROLLBACK TRANSACTION;
    END

GO

Answer 1

当您使用FOR DELETE时，您认为在删除语句完成后将触发此TRIGGER。要在DELETE之前验证条件，您需要使用INSTEAD OF DELETE。您的触发器声明将是：

CREATE TRIGGER trg_del ON Projektbefattningar
INSTEAD OF DELETE
AS

现在要确认您的删除声明，您需要包含删除声明，它不会被删除。最后的程序将是这样的：

CREATE TRIGGER trg_del ON Projektbefattningar

INSTEAD OF DELETE
AS

  SELECT @befNr = Befattningsnr, @pNr = pNr, @EtappNr = Etappnr FROM deleted
-- Not currently using these. Using hard coded values to illustrate my problem

    IF EXISTS (
        SELECT *
        FROM projektbefattningar
        WHERE Befattningsnr = 2 AND pNr = 1 and Etappnr = 1 AND Anställningsnr is not null
        )
    BEGIN
        RAISERROR('Could not delete, Anställningsnr is not null', 16, 1)
        --THROW 50001, 'Could not delete, Anställningsnr is not null', 1;
        ROLLBACK TRANSACTION;
    END
    ELSE
    BEGIN

       DELETE FROM YourTableToDelete Where idOfYourTable in ( Select idOfYourTable from Deleted )
    END

GO

Answer 2

试试这个

CREATE TRIGGER trg_del ON Projektbefattningar
FOR DELETE
AS
SELECT @befNr = Befattningsnr
    ,@pNr = pNr
    ,@EtappNr = Etappnr
FROM deleted

-- Not currently using these. Using hard coded values to illustrate my problem
IF EXISTS (
        SELECT 1
        FROM deleted
        WHERE Befattningsnr = 2
            AND pNr = 1
            AND Etappnr = 1
            AND Anställningsnr IS NOT NULL
        )
BEGIN
    RAISERROR (
            'Could not delete, Anställningsnr is not null'
            ,16
            ,1
            )

    --THROW 50001, 'Could not delete, Anställningsnr is not null', 1;
    ROLLBACK TRANSACTION;
END
GO

sql DELETE触发器不会回滚

2 个答案: