期望用逗号分隔的数组的不同输出

i want to fetch distinct values from an array and also those value should be separated by commas like English,German,French but what i have got is EnglishFrenchGerman.

 <?php 
    $cmd = mysql_query("select language from lang where dispname = 'Sk'");
    while($out = mysql_fetch_array($cmd))
    {
    $res = array_unique($out);  
    $row = implode(",",$res);
    echo "$row";
        }           
    ?>  

If you cannot see why the code does not do what you expect then dump data out during the processing. Try this :-

<?php 
    $cmd = mysql_query("select language from lang where dispname = 'Sk'");
    while($out = mysql_fetch_array($cmd))
    {
        echo '<pre>' . print_r($out,true) . '</pre>';
        $res = array_unique($out);  
        echo '<pre>' . print_r($res,true) . '</pre>';
        $row = implode(",",$res);
        echo $row;
    }           
?>