How to make these queries to subqueries?

Question

How to make this into a single query. I have formulated the following query:

$msgs=mysql_query("select m.subject, m.msg from message as m, message_users as mu where m.id=mu.msg_id and mu.user_id=$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 />";
            }
        }
}

because of the length of the query it runs really slow.

I edited the code now like this but it says mysql_fetch_array() excepts parameter 1 to be resource Boolean is given...

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

Answer 1

Try this query:

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

I could improve the answer if you explain me what do you want to do: What is the structure of message_users and message tables and why do you want to join both of them?

EDIT: What about this?

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

The problem is that you'll get one row for each message and for each receiver, but with PHP you could group the information (is more efficient than 3 queries in a loop)

Answer 2

try this query

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

I have joined all the tables so that all necessary fields are returned