如何使这些查询进行子查询？

如何将其制作为单个查询。我制定了以下查询：如何使这些查询进行子查询？

$msgs=mysql_query("select m.subject, m.msg from message as m, message_users as mu where m.id=mu.msg_id and mu.user_id=$u_id order by dateof_msg desc"); 
while($row1=mysql_fetch_array($msgs)) 
{ 
     $total_msg = $row1['msg']; 
     $own_id = mysql_query("select owner_id from message where msg='$total_msg' "); 
     while($o_id=mysql_fetch_array($own_id)) 
     { 
      $owners_id = $o_id['owner_id']; 
      $uname = mysql_query("select name from users where id='$owners_id'"); 

      while($username=mysql_fetch_array($uname)) 
      { 
       $sen_name = $username['name']; 
       echo $sen_name."&nbsp;&nbsp;".$owners_id."&nbsp;&nbsp;&nbsp;&nbsp;".$total_msg."<br />"; 
      } 
     } 
}

由于查询的运行时间确实很慢。

我现在编辑的这样的代码，但它说mysql_fetch_array（）节选参数1是资源布尔给出...

$userlist = mysql_query("select m.subject, m.msg, m.owner_id, u.name, u.id, mu.msg_id, mu.user_id from message as m, message_users as mu, users as u 
            m inner join u on (m.owner_id = u.id) 
            m inner join mu on(m.id=mu.msg_id) and 
            where mu.user_id='$u_id' order by dateof_msg desc") or mysql_error(); 
       while($row=mysql_fetch_array($userlist)) 
       { 
        $sendername = $row['name']; 
        echo $sendername; 
       }

来源

2013-03-01 AndRaGhu

这是因为该查询不正确。把这个：'$ userlist = mysql_query（“...”）或死（mysql_error（））;'你会看到错误。 – RainHeart257 2013-03-01 13:21:12

试试此问题：

select m.subject, m.msg, m.owner_id, users.name 
from message as m, message_users as mu 
    inner join users on (message.owner_id = users.id) 
where m.id=mu.msg_id and mu.user_id=$u_id order by dateof_msg desc

如果你向我解释你想做什么，我可以改进答案：message_users和消息表的结构是什么，你为什么要加入他们？

编辑：这是怎么回事？

select m.id, m.subject, m.msg, owner.id, 
    owner.name, receivers.id, receivers.name 
from message as m 
    inner join message_users as mu on (m.id = mu.msg_id) 
    inner join users as owner on (m.owner_id = owner.id) 
    inner join users as receivers on (m.user_id = receivers.id) 
where receivers.user_id=$u_id 
order by dateof_msg desc

的问题是，你会得到一个排的每个消息和每个接收器，但用PHP，你可以组的信息（比一回路3次的查询更有效）

来源

2013-03-01 11:24:54 RainHeart257

开发消息通信系统消息表具有发送者的信息和message_users表具有谁是消息的接收者。 – AndRaGhu 2013-03-01 11:31:59

而在此代码中，您试图获取所有消息及其所有者并将其列入列表中，是不是？在这种情况下，你是否真的需要从message_users获取数据？ – RainHeart257 2013-03-01 11:39:22

雅我需要从message_users表中得到接收者ID .. – AndRaGhu 2013-03-01 11:41:35

尝试此查询

select m.subject, m.msg, m.owner_id, u.name 
from message as m, message_users as mu, users as u 
where m.id=mu.msg_id and mu.user_id=<userId> and msg=<MESSAGE> and u.id = mu.userId 
order by dateof_msg desc

我已经参加了所有所有必要的字段返回

来源

2013-03-01 11:21:31 Meherzad

如何使这些查询进行子查询？

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