批量更新数据时候,Inserted和Deleted临时表也是批量的,但触发器只会调用执行一次!两个概念千万不要弄混淆!
错误的理解;例如:创建在A表上创建了一个Update触发器,里面写的是Update一条记录;当在A表进行update数据时候,会调用执行触发器一次,不可能因为触发器中有Update语句会又执行一次,那样岂不是死循环了。。
本文章转载:http://blog.csdn.net/baronyang/article/details/5174734
原来update触发器只会被update触发一次,无论更新的记录数是多少,以下为验证代码
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CREATE TABLE TMP_TABLE1 (PersonCode VARCHAR(20) NOT
NULL PRIMARY KEY,[NAME] VARCHAR(50) NULL,DepCode VARCHAR(20) NULL,Amount MONEY null)CREATE TABLE TMP_TABLE2 (PersonCode VARCHAR(20) NOT
NULL PRIMARY KEY,[NAME] VARCHAR(50) NULL,DepCode VARCHAR(20) NULL,Amount MONEY null)GOINSERT INTO TMP_TABLE1(PersonCode,[NAME],Amount)VALUES(‘00001‘,‘AAA1‘,1000)INSERT INTO TMP_TABLE1(PersonCode,[NAME],Amount)VALUES(‘00002‘,‘AAA2‘,1000)INSERT INTO TMP_TABLE1(PersonCode,[NAME],Amount)VALUES(‘00003‘,‘AAA3‘,1000)INSERT
INTO TMP_TABLE1(PersonCode,[NAME],Amount)VALUES(‘00004‘,‘AAA4‘,1000)INSERT
INTO TMP_TABLE1(PersonCode,[NAME],Amount)VALUES(‘00005‘,‘AAA5‘,1000)INSERT
INTO TMP_TABLE2(PersonCode,[NAME],Amount)VALUES(‘00001‘,‘AAA1‘,1000)INSERT
INTO TMP_TABLE2(PersonCode,[NAME],Amount)VALUES(‘00002‘,‘AAA2‘,1000)INSERT
INTO TMP_TABLE2(PersonCode,[NAME],Amount)VALUES(‘00003‘,‘AAA3‘,1000)INSERT
INTO TMP_TABLE2(PersonCode,[NAME],Amount)VALUES(‘00004‘,‘AAA4‘,1000)INSERT
INTO TMP_TABLE2(PersonCode,[NAME],Amount)VALUES(‘00005‘,‘AAA5‘,1000)GOAlter TRIGGER dbo.tmp_table1_update ON
tmp_table1AFTER UPDATEASSELECT
* INTO #INS FROM INSERTEDDECLARE
@PersonCode VARCHAR(20),@Amount MONEYIF UPDATE(Amount)BEGIN SELECT
@personcode=personcode,@Amount=Amount FROM
#INS UPDATE
TMP_TABLE2 SET
Amount =@Amount WHERE
PersonCode=@PersonCode ENDGOUPDATE
TMP_TABLE1 SET
Amount = 2000select
* from TMP_TABLE1SELECT
* FROM TMP_TABLE2 |
然后再更新,发现TMP_TABLE1的Amount字段值都更新为2000,但TMP_TABLE2的Amount值只有第一条记录更新了,下面改一下触发器
批量更新数据小心SQL触发器的陷阱,布布扣,bubuko.com
原文:http://www.cnblogs.com/zfanlong1314/p/3578323.html