与帖子mysql的顶级用户

Question

我有2桌用户|帖子。

的posts结构是：

[post_id | post_user_id]

users的结构是：

[user_id | user_name | user_password]

现在我想要得到的前5名用户与帖子

编辑1：

 $cod_sql = "select u.user_name, count(*) as 'TotalNumberofPosts' 
from users u 
    join posts p 
    on u.user_id=p.post_user_id 
group by user_name 
order by count(*) desc 
limit 5"; 
     $top10 = mysql_query($cod_sql1) or die (error_sql(mysql_error(),__LINE__,__FILE__)); 

      echo '<div class="head_panel">Members</div> 
        <div class="body_panel"> 
       <table border="1" width="100%"> 
        <tr> 
        </tr> 
        <tr class="tr3"> 
       Top5 : 
        </tr>'; 

    if ($top10 === FALSE) 
    { 
     // An error has occured 
     print "There was an error running the query" . mysql_error(); 
    } else { 
     while ($row = mysql_fetch_assoc($top10)) 
     { 
      print "This is some data from a row<BR />"; 
      print "Name: ($row) <BR />"; 
     } 
    } 

      } 
     break; 

Answer 1

以下代码将计算每位用户的帖子总数，并只显示前5张海报。 SQL Fiddle demonstration。

select u.user_name, count(*) as 'TotalNumberofPosts' 
from users u 
    join posts p 
    on u.user_id=p.post_user_id 
group by user_name 
order by count(*) desc 
limit 5 

Answer 2

我想这会做。我现在不能验证剧本，所以告诉我它是否可行。

select * 
from users 
where exists (
    select * from posts 
    where users.user_id=posts.post_user_id) 
order by users.user_id 
limit 5