需求:
表1,文章表,
表2,评论表,
第一种实现方式:
SELECT a.id,a.title,a.content,a.type_id,count(b.id) as d from message as a LEFT JOIN comment as b on a.id=b.id GROUP BY b.id ORDER BY d desc
第二种实现方式:
SELECTa.id,a.title,a.content,a.type_id,if(ISNULL(c)=1,0,c)asdfrommessageasaLEFTJOIN
(SELECTid,count(id)ascfromcommentGROUPBYid)asb
ona.id=b.idORDERBYcdesc
结果:
mysql sql语句 查询文章表 评论表(根据评论表文章评论次数排序查询出文章count group left join)