批量更新的触发器问题

原文连接：http://blog.csdn.net/baronyang/article/details/5174734

原来update触发器只会被update触发一次，不管更新的记录数是多少，如下为验证代码

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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)

GO
INSERT 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)

GO
Alter TRIGGER dbo.tmp_table1_update ON tmp_table1
AFTER UPDATE
AS
SELECT * INTO #INS FROM INSERTED
DECLARE @PersonCode VARCHAR(20),@Amount MONEY
IF UPDATE(Amount)
BEGIN
  SELECT @personcode=personcode,@Amount=Amount FROM #INS
  UPDATE TMP_TABLE2 SET Amount =@Amount WHERE PersonCode=@PersonCode
END

GO

UPDATE TMP_TABLE1 SET Amount = 2000
select * from TMP_TABLE1
SELECT * FROM TMP_TABLE2

而后再更新,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

Alter TRIGGER dbo.tmp_table1_update ON tmp_table1
AFTER UPDATE
AS
SELECT * INTO #INS FROM INSERTED
DECLARE @PersonCode VARCHAR(20),@Amount MONEY
IF UPDATE(Amount)
BEGIN
    DECLARE AmountCursor CURSOR FOR
    SELECT personcode,Amount FROM #INS
    OPEN AmountCursor
    FETCH NEXT FROM AmountCursor INTO @PersonCode,@Amount
    WHILE @@FETCH_STATUS=0--0为Fetch语句已成功，-1为Fetch语句失败或不在结果集中，-2提取的行不存在
    BEGIN
        UPDATE TMP_TABLE2 SET Amount =@Amount WHERE PersonCode=@PersonCode
        FETCH NEXT FROM AmountCursor INTO @PersonCode,@Amount
    END
    CLOSE AmountCursor
    DEALLOCATE AmountCursor
END

更新触发器后，一切正常。

总结：为了保险起见，update触发器仍是要用游标来处理，才能保证所有触发执行.