如何在 SQL Server 触发器中复制插入、更新、删除的行

Question

如果用户更改表 HelloWorlds，那么我想要“他们执行的操作”、执行时间，并将原始行的副本插入到 HelloWorldsHistory。

由于列的长度，我希望避免插入、更新和删除操作的单独触发器。

我试过了：

create trigger [HelloWorlds_After_IUD] on [HelloWorlds]
FOR insert, update, delete
as
if @@rowcount = 0 
return
if exists (select 1 from inserted) and not exists (select 1 from deleted)
begin
insert into HelloWorldHistory (hwh_action, ..long column list..)
select 'INSERT', helloWorld.id, helloWorld.text ... and more from inserted
end
else
    if exists (select 1 from inserted) and exists (select 1 from deleted)
    begin
insert into HelloWorldHistory (hwh_action, ..long column list..)
select 'UPDATE', helloWorld.id, helloWorld.text ... and more from deleted 
    end
    else
    begin
insert into HelloWorldHistory (hwh_action, ..long column list..)
select 'DELETE', helloWorld.id, helloWorld.text ... and more from deleted
    end
end

我从未见过插入出现，但我看到了更新。我将尝试 3 个单独的触发器，但维护列列表不会很有趣。

Answer 1

试试这样的：

CREATE TRIGGER YourTrigger ON YourTable
   AFTER INSERT,UPDATE,DELETE
AS

DECLARE @HistoryType    char(1) --"I"=insert, "U"=update, "D"=delete

SET @HistoryType=NULL

IF EXISTS (SELECT * FROM INSERTED)
BEGIN
    IF EXISTS (SELECT * FROM DELETED)
    BEGIN
        --UPDATE
        SET @HistoryType='U'
    END
    ELSE
    BEGIN
        --INSERT
        SET @HistoryType='I'
    END
    --handle insert or update data
    INSERT INTO YourLog
            (ActionType,ActionDate,.....)
        SELECT
            @HistoryType,GETDATE(),.....
            FROM INSERTED

END
ELSE IF EXISTS(SELECT * FROM DELETED)
BEGIN
    --DELETE
    SET @HistoryType='D'

    --handle delete data, insert into both the history and the log tables
    INSERT INTO YourLog
            (ActionType,ActionDate,.....)
        SELECT
            @HistoryType,GETDATE(),.....
            FROM DELETED

END
--ELSE
--BEGIN
--    both INSERTED and DELETED are empty, no rows affected
--END

Answer 2

您需要关联（匹配）插入和删除列中的行。这样的事情应该会更好。

create trigger [HelloWorlds_After_IUD] on [HelloWorlds]
FOR insert, update, delete
as

insert into HeloWorldsHistory
select 'INSERT', helloWorld.id, helloWorld.text ... and more 
from inserted
where myKeyColumn not in (select myKeyColumn from deleted)

insert into HeloWorldsHistory
select 'DELETE', helloWorld.id, helloWorld.text ... and more 
from deleted
where myKeyColumn not in (select myKeyColumn from inserted)

insert into HeloWorldsHistory
select 'UPDATE', helloWorld.id, helloWorld.text ... and more 
from inserted
where myKeyColumn in (select myKeyColumn from deleted)