select a.area_id,a.rsum,IFNULL(b.rcount,0) rcount from (select area_id,sum(balance_no) rsum from user group by area_id) a left jion(select a.area_id,count(b.policy_no) rcount from user a, order b where a.userid=b.userid group by a.area_id) b on (a.area_...
mysql中两表联合查询，需要分组去重
select a.area_id,a.rsum,IFNULL(b.rcount,0) rcount from (select area_id,sum(balance_no) rsum from user group by area_id) a left jion(select a.area_id,count(b.policy_no) rcount from user a, order b where a.userid=b.userid group by a.area_id) b on (a.area_id=b.area_id)2013-11-14
