Вывод данных из бд поочередно

<?
$id = "id";             
$sql = mysql_query("SELECT  `photo_id`,`cat`,`id`,`img`, `category`,`text`   FROM
 `gallery_category`, `3_images` where `cat`=$id ORDER BY `id`"); 
 
if($sql)
{
while ($row = mysql_fetch_array($sql)) {
    
echo '    <h2 class="title" data-selector="h2">'.$row['category'].'</h2>
 
<p class="sep-bottom desc-text editContent" data-selector="p">'.$row['text'].'</p>';
 
echo '
<a href="show_room.php?cat='.$row['photo_id'].'">
<img src="images/kuchnie/_nowoczesne/F1/n1_1/'.$row['img'].'"></a>';    
    
    }
}
     
else
{
    print mysql_error();
}   
?>

<?php
$db = mysqli_connect("localhost", "root", "usbw", "cyber");
$sql = mysqli_query($db, "SELECT * , GROUP_CONCAT( DISTINCT 3I.`img` ORDER BY 3I.`img` ASC SEPARATOR ', ' ) AS img
FROM gallery_category GC
INNER JOIN 3_images 3I ON 3I.cat = GC.id
GROUP BY GC.id");
while ($row = mysqli_fetch_array($sql)) {
    echo '   <h2 class="title" data-selector="h2">'.$row['category'].'</h2><p class="sep-bottom desc-text editContent" data-selector="p">'.$row['text'].'</p>';
    foreach (explode(", ", $row['img']) as $show_img) {
        $sql_img_id = mysqli_query($db, "SELECT photo_id FROM 3_images WHERE `img` = '".$show_img."'");
        $row_img_id = mysqli_fetch_array($sql_img_id);
        echo '<a href="show_room.php?cat='.$row_img_id['photo_id'].'"><img src="'.$show_img.'"></a>';
    }
}
?>