一个简单的 运用游标的实例

declare @infoID int;

declare @counts int;

declare myTask cursor for select infoid from T_DatatABLE

 

open myTask;

 

--fetch  city code 

fetch next  from myTask into @infoID;

 

while(@@fetch_status=0)

begin

select @counts= count(*) from  T_DatatABLE  where infoid=@infoID group by infoid 

if @counts>1

begin

delete top(@counts-1) from   T_DatatABLE   where infoid=@infoID

end

fetch next  from myTask into @infoID;

end

close myTask;

deallocate myTask;

 

感觉游标在处理较大数据时的性能很不好，很多时间都出现有超时现象，不怎建议用！