将条件添加到mysql查询并再次获取

Question

I have 3 queries which I run which are nearly identical, the latter two have an AND condition.

Main query:

$mess = $mysqli->prepare("SELECT * from ( SELECT cm.id ,cm.userid,cm.message,cm.voteup,cm.votedown,cm.date
                        FROM chat_messages cm 
                        INNER JOIN members m  ON m.id =cm.userid
                        INNER JOIN chat_settings cs ON cs.id = cm.room_id 
                        WHERE cm.setting_id = ?          
                        ORDER BY cm.date DESC LIMIT 30 ) ddd
                        ORDER BY date ASC ");
$mess->bind_param("i", $room);                              
$mess->execute();
$mess->store_result();

$mess->bind_result($chatid,$chat_userid,$message,$voteup,$votedown,$date);
while($row = $mess->fetch()){
    //im fetching here in my <div class='div1' >
}

Then, in the second div I have to add an AND condition:

$mess2 = $mysqli->prepare("SELECT * from ( SELECT cm.id ,cm.userid,cm.message,cm.voteup,cm.votedown,cm.date
                        FROM chat_messages cm 
                        INNER JOIN members m  ON m.id =cm.userid
                        INNER JOIN chat_settings cs ON cs.id = cm.room_id
                        WHERE cm.setting_id = ?    AND voteup - votedown >= 5      
                        ORDER BY cm.date DESC LIMIT 30 ) ddd
                            ORDER BY date ASC ");
$mess2->bind_param("i", $room);                              
$mess2->execute();
$mess2->store_result();

$mess2->bind_result($chatid,$chat_userid,$message,$voteup,$votedown,$date);
while($row2 = $mess2->fetch()){
    //im fetching here in my <div class='div2' >
}

Lastly, in the third div I have a slightly different AND condition:

$mess3 = $mysqli->prepare("SELECT * from ( SELECT cm.id ,cm.userid,cm.message,cm.voteup,cm.votedown,cm.date
                        FROM chat_messages cm 
                        INNER JOIN members m  ON m.id =cm.userid
                        INNER JOIN chat_settings cs ON cs.id = cm.room_id 
                        WHERE cm.setting_id = ?    AND votedown - voteup >= 5      
                        ORDER BY cm.date DESC LIMIT 30 ) ddd
                            ORDER BY date ASC ");
$mess3->bind_param("i", $room);                              
$mess3->execute();
$mess3->store_result();

$mess3->bind_result($chatid,$chat_userid,$message,$voteup,$votedown,$date);
while($row3 = $mess3->fetch()){
    //im fetching here in my <div class='div3' >
}

Everything works BUT doing this near-same query seems clumsy. Is it possible to construct the same thing with only one query? I have used $mess->data_seek(0); but its not helping because I didn't add my condition to the query.

Answer 1

Just go for PhP to filter your data instead of triple query your database. In this case you can figure out to go for this solution because you call 3 times your query with the same parameter :

    $mess3  =   $mysqli->prepare("  SELECT    * 
                                    FROM      ( SELECT  cm.id ,
                                                        cm.userid,
                                                        cm.message,
                                                        cm.voteup,
                                                        cm.votedown,
                                                        cm.date
                                                FROM        chat_messages cm 
                                                INNER JOIN  members m  ON m.id =cm.userid
                                                INNER JOIN  chat_settings cs ON cs.id = cm.room_id 
                                                WHERE       cm.setting_id = ?    
                                                AND         votedown - voteup >= 5      
                                                ORDER BY    cm.date DESC LIMIT 30 ) ddd
                                    ORDER BY   date ASC ");
$mess3->bind_param("i", $room);                              
$mess3->execute();
$mess3->store_result();
$mess3->bind_result($chatid,$chat_userid ,$message,$voteup,$votedown ,$date);

while($row = $mess3->fetch()){
  $voteup     =   $row['voteup'];
  $votedown   =   $row['votedown'];

  addToDiv1($row);

  if( $voteup - $votedown >= 5 ) {
    addToDiv2($row);
  }

  if( $votedown - $voteup >= 5 ) {
    addToDiv3($row);
  } 
}

Answer 2

I will just give an answer based specifically on cleaning up your code. Technically you will still make the 3 calls in this scenario, but it will be cleaner because you include one function only, you don't see the script behind it.

As I mentioned, I am not an SQL aficionado so I can not give a good solution there (maybe you can use GROUP BY and perhaps an OR clause...I don't really know...). If I were to do this, I would do a function that can return all the options:

/core/functions/getChatMessages.php

function getChatMessages($settings,$mysqli)
    {
        $id   = (!empty($settings['id']))? $settings['id'] : false;
        $type = (!empty($settings['type']))? $settings['type'] : false;
        $max  = (!empty($settings['max']))? $settings['max'] : 30;
        $mod  = '';
        // No id, just stop
        if(!is_numeric($id))
            return false;
        // equation one
        if($type == 'up')
            $mod = ' AND voteup - votedown >= 5';
        // equation two
        elseif($type == 'down')
            $mod = ' AND votedown - voteup >= 5';

        $mess = $mysqli->prepare("SELECT * from ( SELECT cm.id ,cm.userid,cm.message,cm.voteup,cm.votedown,cm.date
                            FROM chat_messages cm 
                            INNER JOIN members m  ON m.id =cm.userid
                            INNER JOIN chat_settings cs ON cs.id = cm.room_id 
                            WHERE cm.setting_id = ? {$mod}     
                            ORDER BY cm.date DESC LIMIT {$max} ) ddd
                            ORDER BY date ASC");
        $mess->bind_param("i", $id);
        $mess->execute();
        $mess->store_result();
        $mess->bind_result($chatid, $chat_userid, $message, $voteup, $votedown, $date);
        while($mess->fetch()){
            $result[] = array(
                            'chatid'=>$chatid,
                            'chat_userid'=>$chat_userid,
                            'message'=>$message,
                            'voteup'=>$voteup,
                            'votedown'=>$votedown
                        );
        }
        // Send back the data
        return (!empty($result))? $result : array();
    }

To use:

// Include our handy function
require_once('/core/functions/getChatMessages.php');
// Store our id for use
$settings['id'] = 100;
// Should get 30 from first select
$voteGen = getChatMessages($settings,$mysqli);
// Should get 30 from second select
$settings['type'] = 'up';
$voteUp = getChatMessages($settings,$mysqli);
// Should get 15 from third select
// Just for the heck of it, I added in a limit settings
$settings['max'] = 15;
$settings['type'] = 'down';
$voteDown = getChatMessages($settings,$mysqli);

Now that you have these stored, just use a foreach loop to place them into your view. The good side of this is that you can call this where ever and when ever since the function only returns data. It allows you to work with the data in a view or non-view situation. Side note, I use PDO, so if there is something ineffective with the way the mysqli is fetching, that will be why. It's probably just best to fetch an assoc array to return...