oracle下:
update housea a set a.extendinfo=(select b.extendinfo from houseb b where a.houseid=b.houseid)
where a.isimage=1 and a.extendinfo is null and exists(select 1 from houseb b where a.houseid=b.houseid)
sqlserver下:
update a set a.extendinfo=b.extendinfo from housea a,houseb b where a.houseid=b.houseid
兩者各不通用.第二種更簡潔
下面是一個存儲過程,爲更新某條件之外的一部分數據.
alter procedure TQ_leasehouse
as
declare @code varchar(20)
declare cc cursor for select managercode from mlsheadcompany where companycode=201001472
open cc
fetch next from cc into @code while (@@FETCH_STATUS=0)
begin
declare @updnum int
select @updnum = COUNT(1) from rent_house.dbo.house_lease_sh_mls where agentcode=@code and registdate>CONVERT(datetime,GETDATE(),120)
update a set registdate=GETDATE() from (select * from (select registdate,ROW_NUMBER() over(order by registdate) rn
from rent_house.dbo.house_lease_sh_mls where agentcode=@code and registdate<CONVERT(datetime,GETDATE(),120)) b where rn<120-@updnum) a
fetch next from cc into @code
end
close cc
deallocate cc