MSSQL中循环表

在很多ERP中进行表循环，是非常简单的。如QAD中用For each table就可以循环表，AX中用While select table。

　　

在MSSQL中，可以通过两种方式进行表循环。

1、通过游标。　

declare @result table
(
 custid int,
 ordermonth datetime,
 qty int,
 runqty int,
 primary key(custid,ordermonth)
);

declare 
  @custid as int,
  @prvcustid as int,
  @ordermonth as datetime,
  @qty as int,
  @runqty as int;
declare c cursor fast_forward for    --定义游标
select custid,ordermonth,qty
from Sales.CustOrders
order by custid,ordermonth;

open c    --打开游标
fetch next from c into @custid,@ordermonth,@qty;
select @prvcustid = @custid,@runqty = 0;
while @@fetch_status = 0    --当不是最后一行记录时，函数返回0
begin
    --Do something 
end
close c;    --关闭游标
deallocate c;    --释放游标

2、通过特定ID。

declare @max int
declare @i int
select ROW_NUMBER() over (order by UnitId) as 'Id',RECID into #temp from UNIT
select @max=max(Id) from #temp
set @i = 1
while (@i <= @max)
begin
if @i = 10
begin
select * from UNIT where RECID = (select RECID from #temp where ID = @i) --11125166
break
end
set @i = @i + 1
end

drop table #temp