php从数据库查询email是否已经存在

php从数据库查询email是否已经存在

// Use this
$email_is_valid = valid_email($email, $db);
 
// Function
function valid_email ($email, $db) {
     
    $r_email = $db->prepare('SELECT COUNT(id) FROM inscriptions WHERE email = ?');
    $r_email->execute(array($email));
    $r_email_count = $r_email->fetchAll();
     
    if ($r_email_count[0][0] == 0):
         
        if (!filter_var($email, FILTER_VALIDATE_EMAIL)):
            return true;
        else:
            return false;
        endif;      
         
    else:
        return true;
    endif;
}