problem with empty values in a database

I have a function which I use all over the place to pull users friends out of a database. However I recently had to delete a few users for causing problems on the forums, this has given me a few "Trying to get property of non-object" problems and I have traced it down to this function.

function isFriend($user_id, $friend_id){
    $this->db->from('friends')开发者_开发百科;
    $this->db->where('user_id', $user_id);
    $this->db->where('friend_id', $friend_id);
    $this->db->where('removed', 0);
    $query = $this->db->get(); 
    $result = $query->result();
    return count($result);
}

Does anyone know how I can adjust this function to ignore deleted users?

If all you're doing is counting the results you can try this instead:

$this->db->count_all_results();

Like this:

function isFriend($user_id, $friend_id)
{
    $num = $this->db
        ->from('friends')
        ->where('user_id', $user_id)
        ->where('friend_id', $friend_id)
        ->where('removed', 0)
        ->from('TABLE_NAME')
        ->count_all_results();

    return $num;
}

It should return 0 if there are no results, whereas $query in your current function (I believe) may not return an object you can call result() on (hence your error).

http://codeigniter.com/user_guide/database/active_record.html

$this->db->count_all_results();

Permits you to determine the number of rows in a particular Active Record query. Queries will accept Active Record restrictors such as where(), or_where(), like(), or_like(), etc. Example:

echo $this->db->count_all_results('my_table'); // Produces an integer, like 25

$this->db->like('title', 'match');
$this->db->from('my_table'); echo
$this->db->count_all_results(); // Produces an integer, like 17

There may be "better" ways, but without knowing the guts of your application it's hard to say.

why did you actualy remove them from database when you have the flag "removed" ? Anyway, i think you should also remove the connections of those removed users, i don't see anything wrong with the function.

Trying to alter the function to work, it's just a hack and it's not good practice.

I think the function itself looks fine but it seem likely your errors are caused when the query returns 0 results.

if the removed col in the friends table or the users table?

Maybe you should perform a join to the users table.