Question

我真的不熟悉使用MS SQL的触发器。这是我使用Oracle SQL进行的触发。

create or replace trigger a4history
after update or delete on STUDENT
for each row
begin
    if updating then
        insert into SHISTORY (SHistoryID,StudentID,RoomNo,Event)
 VALUES ('SH' || sseq.nextval,:old.StudentID,:old.RoomNo,'UPDATE');
    elsif deleting then
        insert into SHISTORY (SHistoryID,StudentID,RoomNo,Event)
 VALUES ('SH' || sseq.nextval,:old.StudentID,:old.RoomNo,'DELETE');
    end if;
end;

create or replace trigger b4student
before insert on STUDENT
for each row
declare
    noroom number;
begin
    select RoomNo INTO noroom
    FROM ROOM
    where RoomID = :new.RoomID;
    :new.RoomNo := noroom;
end;

在MS SQL中触发之后还是之前？

Answer 1

这是您可以使用的示例插入触发器模板，请注意，所有更改的行都在临时表INSERTED中。如果要编写更新触发器而不是插入触发器，则仍然必须使用INSERTED表来查找更改。祝你好运

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TRIGGER [dbo].[tbl_Mydata_INSERT]
   ON [dbo].[tbl_Mydata]
   AFTER INSERT
AS 
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    -- Update basedata after insert
    UPDATE 
        E SET 
        E.Field = 'something'
    FROM [tbl_Mydata] E
        INNER JOIN INSERTED I ON I.ID = E.ID


END

Answer 2

相应的触发器将是instead of触发器：

create or replace trigger b4student instead of insert as
begin
    insert into b4student ( . . ., roomid, . . . )
        select . . ., r.roomid, . . .
        from inserted i join
             room r
             on i.roomid = r.roomid;
end;

我认为您也可以这样做：

create or replace trigger b4student instead of insert as
begin
    insert into b4student
        select i.*;

    update b
        set roomid = r.roomno
        from b4student b join
             inserted i
             on b.<primary key> = i.<primary key> join  -- whatever the primary key is
             room r
             on i.roomid = r.roomid;
end;

不知道如何将Oracle触发器转换为Microsoft SQL Server Management Studio触发器

2 个答案: