mysql多表查询 查询排序
有 ask 问题表 和 answer回答表 回答表中的ask_id和 ask表中的id对应
1、查询
/*
查询回答了的
*/
select a.id,a.title,count(b.ask_id) as num from phome_ecms_ask a,phome_ecms_answer b where a.id=b.ask_id group by a.id order by num desc
2、将ask问题表中的问题 按回答数量排序
/*
查询所有的问题 按回答数排序
*/
select a.id,a.title,count(b.ask_id) as num from phome_ecms_ask a left join phome_ecms_answer b on a.id=b.ask_id group by a.id order by num desc