查询一个表的id 并统计在另一个表出现的次数

select p.title,p.pic,p.id,p.author, p.time,p.is_ok,count(pz.post_id) c
FROM  pre_post p,pre_post_zan pz
WHERE pz.post_id = p.id and pz.zan=1 
group by(pz.post_id) 
ORDER BY c desc