sql 循环语句几种方式

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--第一

declare @orderNum varchar(255)

create table #ttableName(id int identity(1,1),Orders varchar(255))

declare @n int,@rows int

insert #ttableName(orders) select orderNum from pe_Orders where orderId<50

--select @rows=count(1) from pe_Orders

select @rows =@@rowcount

set @n=1

while @n<=@rows

begin

select @orderNum=OrderNum from PE_Orders where OrderNum=(select Orders from #ttableName where id=@n)

print (@OrderNum)

select @n=@n+1

end

drop table #ttableName

--第二

declare @orderN varchar(50)--临时变量，用来保存游标值

declare y_curr cursor for --申明游标为orderNum

select orderNum from pe_Orders where orderId<50

open y_curr --打开游标

fetch next from Y_curr into @orderN ----开始循环游标变量

while(@@fetch_status=0)---返回被 FETCH 语句执行的最后游标的状态，而不是任何当前被连接打开的游标的状态。

begin

print (@orderN)

update pe_Orders set Functionary+@orderN where orderNum=@orderN --操作数据库

fetch next from y_curr into @orderN --开始循环游标变量

end

close y_curr--关闭游标

deallocate y_curr --释放游标

--第三

select orderNum,userName,MoneyTotal into #t from pe_Orders po

DECLARE @n int,@error int

--set @n=1

set @error=0

BEGIN TRAN --申明事务

declare @orderN varchar(50),@userN varchar(50) --临时变量，用来保存游标值

declare y_curr cursor for --申明游标为orderNum,userName

select orderNum,userName from PE_Orders where Orderid<50

open y_curr

fetch next from y_curr into @orderN,@userN

while @@fetch_status = 0

BEGIN

select isnull(sum(MoneyTotal),0),orderNum from #t where username=@userN

--set @n=@n+1

set @error=@error+@@error--记录每次运行sql后是否正确 0正确

fetch next from y_curr into @orderN,@userN

END

IF @error=0

BEGIN

commit tran --提交

END

ELSE

BEGIN

ROLLBACK TRAN --回滚

END

close y_curr

deallocate y_curr

DROP TABLE #t

-- ╔════════╗
-- =============================== ║ if语句使用示例 ║
-- ╚════════╝
declare @a int
set @a=12
if @a>100
begin
print @a
end
else
begin
print 'no'
end
-- ╔══════════╗
-- =============================== ║ while语句使用示例 ║
-- ╚══════════╝
declare @i int
set @i=1
while @i<30
begin
insert into test (userid) values(@i)
set @i=@i+1
end
-- 设置重复执行 SQL 语句或语句块的条件。只要指定的条件为真，就重复执行语句。可以使用 BREAK 和 CONTINUE 关键字在循环内部控制 WHILE 循环中语句的执行。本条为以前从网上查找获取！
-- ╔════════╗
-- ================================ ║ 临时表和try ║
-- ╚════════╝
-- 增加临时表
select * into #csj_temp from csj
-- 删除临时表用到try
begin try -- 检测代码开始
drop table #csj_temp
end try
begin catch -- 错误开始
end catch
-- ╔═════════╗
-- =============================== ║ 游标循环读记录 ║
-- ╚═════════╝
declare @temp_temp int
--declare @Cur_Name
--@Cur_Name="aaa"
--------------------------------- 创建游标 --Local(本地游标)
DECLARE aaa CURSOR for select House_Id from House_House where Deleted=0 or deleted is null
----------------------------------- 打开游标
Open aaa
----------------------------------- 遍历和获取游标
fetch next from aaa into @temp_temp
--print @temp_temp
while @@fetch_status=0
begin
--做你要做的事
select * from House_monthEnd where House_Id=@temp_temp
fetch next from aaa into @temp_temp -- 取值赋给变量
--
end
----------------------------------- 关闭游标
Close aaa
----------------------------------- 删除游标
Deallocate aaa
--

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