關於MYSQL加入＆計數

Question

我有2個表查詢：

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

我如何返回以下數據：

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

其中NUM是客戶端ID的次數（計數）在表client_posts發現

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

查詢：

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