如果我有表测试有两列NUM1和NUM2和它下面的触发器,它只是增加对NUM1的刀片NUM2:SQL服务器 - 重写触发器,以避免基于游标的方法
DECLARE @PROC_NEWNUM1 VARCHAR (10)
DECLARE @NEWNUM2 numeric(20)
DECLARE my_Cursor CURSOR FOR SELECT num1 FROM INSERTED;
OPEN my_Cursor
FETCH NEXT FROM my_Cursor into @PROC_NEWNUM1
WHILE @@FETCH_STATUS = 0
BEGIN
select @NEWNUM2 = MAX(num2) from TEST
if @NEWNUM2 is null
Begin
set @NEWNUM2 = 0
End
set @NEWNUM2 = @NEWNUM2 + 1
UPDATE TEST SET num2 = @NEWNUM2 WHERE num1 = @PROC_NEWNUM1
FETCH NEXT FROM my_Cursor into @PROC_NEWNUM1
END
CLOSE my_Cursor
DEALLOCATE my_Cursor
有没有办法使用基于集合的方法重写上述内容?
(如果有人想知道为什么我这样做,这里的背景是: SQL Server A trigger to work on multiple row inserts)
解决方案,而无需使用ROW_NUMBER临时表(SQL 2005年起只):
SELECT @MAXNUM2 = MAX(num2) FROM TEST
if @MAXNUM2 IS NULL
BEGIN
SET @MAXNUM2=0
END
UPDATE TEST
SET num2 = @MAXNUM2 + SubQuery.R
FROM
(
SELECT num1, ROW_NUMBER() OVER (ORDER BY num1) as R FROM inserted
)
SubQuery
INNER JOIN TEST on SubQuery.num1 = TEST.num1
触发器是魔鬼玩具。 。:D – 2010-02-02 11:53:54