有关MYSQL加入和查询的查询计数

Question

我有两张桌子：

clients(client_id, client_name)
client_posts(client_id, website_id, category, posted_by)

如何返回以下数据：

CLIENT_ID    CLIENT_NAME            NUM
    1       test client 1           30
    2       test client 2           17
    3       test client 3           8

其中NUM是在表client_posts中找到客户端ID的次数（次数）

Answer 1

SELECT client_id, client_name, count(*) AS NUM
FROM client_posts cp
LEFT JOIN clients c ON c.client_id = cp.client_id
GROUP BY client_id

Answer 2

查询：

select cl.client_id,cl.client_name,count(cp.client_id) as NUM
 from clients cl 
 left join client_posts cp on (cl.client_id=cp.client_id)
 group by cp.client_id;

Fiddle Example