วิธีตัดค่าซ้ำกันใน sql มันตัดออกยังไงครับ รายละเอียดข้างใน รบกวนทีครับ

$sql = "select distinct id from tb order by id";
$result = mysql_query($sql) or die(mysql_error());
while($data = mysql_fetch_row($result)){
   echo "{$data[0]} - ";
   $sql="select data from tb where id='{$data[0]}' ";
   $result2 = mysql_query($sql) or die(mysql_error());
   while($data2 = mysql_fetch_row($result2)){
        echo "{$data2[0]}, ";
   }
   echo "<br />\n";
}

SELECT
    CONCAT(`id`, ' ', GROUP_CONCAT(DISTINCT `data` ORDER BY `data` SEPARATOR ' , '))
FROM `table`
GROUP BY `id`
ORDER BY `id`

$result = mysql_query("
SELECT
    CONCAT(`id`, ' ', GROUP_CONCAT(DISTINCT `data` ORDER BY `data` SEPARATOR ' , ')) AS `output`
FROM `ชื่อตารางของคุณ`
GROUP BY `id`
ORDER BY `id`
");
while (($row = mysql_fetch_assoc($result))) {
    echo "$row[output]<br />";
}

$sql = "SELECT id, concat_ws( ',', group_concat( distinct data order by data ) ) FROM `b` group by id ";
$result = mysql_query($sql) or die(mysql_error());
while($data = mysql_fetch_row($result)){
   echo "{$data[0]} - {$data[1]} <br />\n";
}

SELECT `group_id`, concat_ws( ',', group_concat( distinct `DurableArticleSet`order by `DurableArticleSet` ) ) FROM `reserve` group by `group_id`