通过一个查询对数据进行分组和计数

Question

This is my table structure in database

I want to get number of likes for each post by counting post field in likes table and display it for every post using foreach loop.

My question is

Is there a way i can do this with one query with JOIN , GROUP BY and COUNT tables and not create multiple queries.

Answer 1

select p.id, p.title, p.content, count(l.id) as likes_count
from posts p
left join likes l on l.post = p.id
group by p.id, p.title, p.content

Answer 2

http://sqlfiddle.com/#!9/bca8ee/1

SELECT p.*, COUNT(l.id)
FROM posts p
LEFT JOIN likes l
ON l.post = p.id
GROUP BY p.id