MySQL – Join part of query to a new query?

I’ve got the following code which queries a table. Then it uses the result to make another query. That result is then used to make a third query.

But how do I grab the userid field from the 2nd query in order to grab a name from a users table and join that to the result of the 3rd query?

Please note once I figure out the code I will convert this to a prepared statement. It’s just easier for me to work with legacy code when figuring out queries.

    $selectaudioid = "SELECT audioid FROM subscribe WHERE userid = $userid";
    $audioResult=$dblink->query($selectaudioid);
    
    if ($audioResult->num_rows>0)   {       
            while ($row = $audioResult->fetch_assoc())  {
                $newaudio = $row[audioid];  
                $getallaudio = "SELECT opid, userid from audioposts WHERE audioid = $newaudio"  ;
                $getallresult = $dblink->query($getallaudio);           
                
                if ($getallresult->num_rows>0)  {                       
                while ($row = $getallresult->fetch_assoc())  {
                    $opid = $row[opid];
                    $opuserid = $row[userid];
                    $getreplies = 
                        "SELECT * from audioposts ap WHERE opid = $opid AND opid                        
                         NOT IN (SELECT opid FROM audioposts WHERE audioposts.opid = '0' )";    
                    $getreplyresults = $dblink->query($getreplies);
                    
                    if ($getreplyresults->num_rows>0)   {
                    while ($row = $getreplyresults->fetch_assoc())  {
                        $dbdata[]=$row;
                }                           
            }                       
        }
    }
 }
}       "SELECT * from audioposts ap WHERE opid = $opid AND opid                        
                         NOT IN (SELECT opid FROM audioposts WHERE audioposts.opid = '0' )";    
                    $getreplyresults = $dblink->query($getreplies);
                    
                    if ($getreplyresults->num_rows>0)   {
                    while ($row = $getreplyresults->fetch_assoc())  {
                        $dbdata[]=$row;
                }                           
             }                      
           }
         }
       }
    } 
echo json_encode($dbdata);

The result I need are rows of json encoded instances of $getreplyresults with the $row[userid] from the original result joined to each row.

Answer

Here’s what I did in the end. Now I just have to figure out how to convert this to a prepared statement in order to avoid malicious injection.

    $selectaudioid = "SELECT audioid FROM subscribe WHERE userid = $userid";
    $audioResult=$dblink->query($selectaudioid);
    
        if ($audioResult->num_rows>0)   {       
            while ($row = $audioResult->fetch_assoc())  {
                $newaudio = $row[audioid];  
                $getallaudio = "
                SELECT ap.audioid, ap.title, us.name FROM audioposts ap                     
                INNER JOIN audioposts a2 ON a2.audioid = ap.opid
                INNER JOIN users us ON us.id = a2.userid 
                WHERE ap.opid = $newaudio AND ap.opid <> '0'
                ";
                
                $getallresult = $dblink->query($getallaudio);           
                
                if ($getallresult->num_rows>0)  {                       
                while ($row = $getallresult->fetch_assoc())  {
                    $dbdata[]=$row;                         
        }}}}