Question

Why does the code below returns 1 although there is no elements in the field group_members ?

$conn = mysql_connect($host,$user,$pass);

@mysql_select_db($db);

$sql = "
    SELECT 
        group_members
    FROM
        tbl_group
    WHERE
        group_id = '6'      
";

$res = mysql_query($sql);

$rows = mysql_num_rows($res);

echo $rows;

?>

Answer 1

The SQL you wrote will select all rows with group_id = 6 and then return the value of the field group_members regardless the content. To get what you want, try:

SELECT group_members FROM tbl_group WHERE group_id = 6 AND group_members <> '' // Depending on type might also be <> NULL or <> 0