PHP function error Notice: Undefined index:

Shortly I need to block a group of users at once according to their role status (banned or not) instead of blocking users one by one. I tried using fk on update cascade to control the role status by making a fk user_role_status column in the users table refers to role_status column in the roles table but without luck because when I change a role status in roles table it changes the whole user_role_status column in users table not only the role I changed then it blocks all users not only the group I want to block because role_status in roles table is not unique and I can't make it unique because its all cells contain value='1', so I deleted the column and gave up that idea

// role_status in roles table is a fk refers to id in statuses table.
 
    statuses_table
    
    id       is_active              
    ------------------
    0          no                        
    1          ok                        
    
    roles_table
    
    id       role              role_status
    --------------------------------------
    1        Admins                1
    2        Editors               1
    3        Users                 1
    
    users_table
    
    id       user_name       user_level       
    ---------------------------------------
    1        Admin               1                                 
    2        Editor1             2                                  
    3        User1               3                                  
    4        Editor2             2                                 
    5        User2               3                                   
    6        User3               3  
             

and this is the function I use

--------------------------------------------------------------
Find role status
--------------------------------------------------------------

function find_by_current_rolStatus($role_status)
{
global $db;
$sql = "SELECT users.id FROM users JOIN roles ON roles.id = users.user_level WHERE roles.role_status = '{$db->escape($role_status)}'";
$result = $db->query($sql);
return($db->num_rows($result) === 0 ? true : false);
}
    
--------------------------------------------------------------
Function for checking if user role status banned or allowed
--------------------------------------------------------------
    
function login_require_roleStatus($require_role_status)
{
global $session;
$current_user = current_user();
$current_user_role_status = find_by_current_rolStatus($current_user['role_status']);//line 155
//if Role status Deactive
if ($current_user['role_status'] === '0')://line 157
$session->msg('Banned');
redirect('home.php',false);
//if user role allowed
elseif($current_user['role_status'] === '1')://line 161
return true;
endif;
}

and I got this error

Notice: Undefined index: role_status in sql.php on line 155
Notice: Undefined index: role_status in sql.php on line 157
Notice: Undefined index: role_status in sql.php on line 161