連接到每個用戶在MySQL

Question

怎麼算的消息我有表newsnews_iduser_id和usersuser_iduser_name 我想MySQL查詢計數附加到每個用戶的消息 像

mad_man = 5 news 
me = 102 news 

Answer 1

我會爲你建議三個詞：SELECT，COUNT和JOIN查看它。

每請求

SELECT u.user_id, COUNT(n.news_id) 
    FROM users u 
    JOIN news n on u.user_id = n.user_id 
GROUP BY u.user_id 

這應該算爲指定表中的每個用戶的所有消息。

Answer 2

SELECT COUNT(*) AS count, users.user_name 
FROM news join users ON news.user_id=users.user_id 
GROUP BY users.user_name