如何在SQL Server中创建before delete触发器？

Question

我想创建一个before删除触发器。当我从表中删除记录时，必须将记录插入到历史记录表中。我如何在SQL Server中执行此操作？

Answer 1

在这种情况下，你可能触发“后”更好做有规律的。这是这种情况最常见的方法。

喜欢的东西

CREATE TRIGGER TRG_AUD_DEL 
ON yourTable 
FOR DELETE 
AS 
    INSERT INTO my_audit_table (col1, col2, ...) 
    SELECT col1, col2... 
    FROM DELETED 

会发生什么事是，当一个记录（或记录！）从您的表中删除，删除的行会被插入到my_audit_table的DELETED表是包含一个虚拟表在删除前立即记录。

另外请注意，触发运行作为delete语句隐含的交易的一部分，因此，如果您删除失败并回滚，触发也将回滚。

Answer 2

你也可以使用INSTEAD OF DELETE

CREATE TRIGGER dbo.SomeTableYouWhatToDeleteFrom 
ON dbo.YourTable 
INSTEAD OF DELETE 
AS 
BEGIN 

    -- Some code you want to do before delete 

    DELETE YourTable 
    FROM DELETED D 
    INNER JOIN dbo.YourTable T ON T.PK_1 = D.PK_1 
END 

Answer 3

这是可以做到在下面的步骤进行，让我们在这个例子说，我使用的客户表：

CREATE TABLE CUSTOMERS(
    ID INT    NOT NULL, 
    NAME VARCHAR (20)  NOT NULL, 
    AGE INT    NOT NULL, 
    ADDRESS CHAR (25) , 
    LAST_UPDATED DATETIME, 
    PRIMARY KEY (ID) 
); 

1. 创造历史：

   CREATE TABLE CUSTOMERS_HIST( 
   ID INT    NOT NULL, 
   NAME VARCHAR (20)  NOT NULL, 
   AGE INT    NOT NULL, 
   ADDRESS CHAR (25) , 
   LAST_UPDATED DATETIME, 
   PRIMARY KEY (ID) 
   ); 
   

2. 触发源表像下面的删除事件：

   CREATE TRIGGER TRG_CUSTOMERS_DEL 
   ON CUSTOMERS 
   FOR DELETE 
   AS 
       INSERT INTO CUSTOMERS_HIST (ID, NAME, AGE, ADDRESS, LAST_UPDATED) 
       SELECT ID, NAME, AGE, ADDRESS, LAST_UPDATED 
       FROM DELETED