mysql - 将多个表的计数加入查询

Question

我想从一个表中选择列并根据另外两个表的连接进行计数，我该怎么做？

这是我写的计数查询:

   SELECT COUNT(*) AS num_review FROM approved_reviews  m, reviews u where 
   m.review_id_=u.id  and u.item_id =? and m.approved=1 

我想加入它

select item_id, item_name, item_price from items ?

我该怎么做？

Answer 1

select * 
from
 (SELECT COUNT(*) AS num_review, u.item_id FROM approved_reviews  m, reviews u where 
   m.review_id_=u.id  and u.item_id =? and m.approved=1 group by u.item_id) count_sub, 
(select item_id, item_name, item_price from items) item_sub
where item_sub.item_id = count_sub.item_id