需要幫助建立一個加入查詢返回頂級評論者

Question

我想在使用單個sql查詢的feburary的月份中返回前五位評論者，但我無法理解我如何加入連接查詢。

這裏是我的表如下所示：

+--------+--------+----------+------------+---------+ 
| postid | userid | username | dateline | comment | 
+--------+--------+----------+------------+---------+ 
| 142535 | 5257 | oshatz | 1094462853 | ....... | 
+--------+--------+----------+------------+---------+ 

這是我已經開始查詢。我想我很接近，但我無法弄清楚。

SELECT username, j.total 
    FROM post as post 
    JOIN (SELECT count(postid) as total 
      FROM post 
     WHERE userid = post.userid 
      AND dateline > 1328054400 
      AND dateline < 1330473600) as j 
WHERE dateline > 1328054400 
    AND dateline < 1330473600 
GROUP 
    BY userid 
LIMIT 10 

我想結果看起來像這樣

+----------+----------+ 
| username | total | 
+----------+----------+ 
| Ken  |  149 | 
+----------+----------+ 
| Bob  |  102 | 
+----------+----------+ 
| Cindy |  100 | 
+----------+----------+ 
| Linsy |  96 | 
+----------+----------+ 
| Greg  |  85 | 
+----------+----------+ 

有人能幫忙打造這樣一個查詢我嗎？謝謝！

Answer 1

SELECT username, count(postid) as total 
FROM post 
WHERE dateline > 1328054400 AND dateline < 1330473600 
GROUP BY userid, username 
ORDER BY total DESC 
LIMIT 10