update 表B Set B_Count= (Select Count(area_id) From 表A,表B where 表A.area_id=表B.area_id )
你这样写肯定不行.Select Count(area_id) From 表A Group By area_id查出来是多条记录,Set B_Count不能同时更新多条呀.
update 表B, Select Count(area_id) as num,area_id From 表A Group By area_id) as tbl_temp Set B_Count=tbl_temp.num where 表A.area_id=tbl_temp.area_id 参照语法: UPDATE tblA,tblA SET tblA.items=tblB.items WHERE tblA.id=tblB.id;
update 表B, (Select Count(area_id) as num,area_id From 表A Group By area_id) as tbl_temp Set 表B.B_Count=tbl_temp.num where 表B.area_id=tbl_temp.area_id是有问题,改了下。呵呵。谢谢楼上的提醒。
按着楼五的朋友去写还是报错呀 update region,(Select Count(id) as num,id From shop Group By id)) as tbl_temp Set shop_count=tbl_temp.num where region.id=tbl_temp.id
update region, (Select Count(id) as num,id From shop Group By id) as tbl_temp Set region.shop_count=tbl_temp.num where region.id=tbl_temp.id你中间多了个")"
update 表B,
Select Count(area_id) as num,area_id From 表A Group By area_id) as tbl_temp
Set B_Count=tbl_temp.num where 表A.area_id=tbl_temp.area_id
参照语法:
UPDATE tblA,tblA SET tblA.items=tblB.items
WHERE tblA.id=tblB.id;
update 表B,
(Select Count(area_id) as num,area_id From 表A Group By area_id) as tbl_temp
Set 表B.B_Count=tbl_temp.num where 表B.area_id=tbl_temp.area_id是有问题,改了下。呵呵。谢谢楼上的提醒。
update region,(Select Count(id) as num,id From shop Group By id)) as tbl_temp Set shop_count=tbl_temp.num where region.id=tbl_temp.id
update
region,
(Select Count(id) as num,id From shop Group By id) as tbl_temp
Set region.shop_count=tbl_temp.num
where region.id=tbl_temp.id你中间多了个")"