I have this script that deletes a users avatar image that is stored in a folder name thumbs and another named images and the image name is stored in a mysql database.

But for some reason the script deletes all the users info for example if the users id is 3 all of the users info like first name last name age and so are deleted as well, basically everything is deleted including the user how do I fix this so only the images and image name is deleted?

Here is the code.

$user_id = '3';

if (isset($_POST['delete_image'])) { 
    $a = "SELECT * FROM users WHERE avatar = '". $avatar ."' AND user_id = '". $user_id ."'";
    $r = mysqli_query ($mysqli, $a) or trigger_error("Query: $a\n<br />MySQL Error: " . mysqli_error($mysqli));
    if ($r == TRUE) {           
        unlink("../members/" . $user_id . "/images/" . $avatar); 
        unlink("../members/" . $user_id . "/images/thumbs/" . $avatar);

        $a = "DELETE FROM users WHERE avatar = '". $avatar ."' AND user_id = '". $user_id ."'";
        $r = mysqli_query ($mysqli, $a) or trigger_error("Query: $a\n<br />MySQL Error: " . mysqli_error($mysqli));
    }
}