CodeIgniter MySQL query where not working after a label - php

Question

i am trying to get result from database conditionally.
like where a = 1 and b != 2 and so much conditions...
here is my code sample
$u = $this->ion_auth->user()->row()->id;
$hide=$this->find_hide_post();
$friend=$this->get_all_contacts();
after this i start my main query
$this->db->where('user_id',$u);
foreach($friend as $fr)
{
foreach($fr as $f)
{
if($f->sub_id !=$u)
{
$this->db->or_where('user_id', $f->sub_id);
}
elseif($f->obj_id !=$u)
{
$this->db->or_where('user_id', $f->obj_id);
}
$this->db->where('time >', $f->time);
}
}
i get good correct result, but whenever i add these lines i didnt get correct result. but i need to remove those posts from result.
foreach($hide as $h)
{
$this->db->where('id !=', $h->post_id);
}
lastly i get through this way
$result=$this->db->get('my_wall');
$row=$result->result();
print_r($row);
the result is:
Array
(
[0] => stdClass Object
(
[id] => 18
[user_id] => 19
[post] =>
[img] => public/users/wall/pic/Messenger14.png
[doc] =>
[video] =>
[link] =>
[link_name] =>
[access_id] =>
[like] => 0
[time] => 1340792296
)
[1] => stdClass Object
(
[id] => 19
[user_id] => 19
[post] => This is my test Documents
[img] =>
[doc] => public/users/wall/doc/19/20745322_temp.pdf
[video] =>
[link] =>
[link_name] =>
[access_id] =>
[like] => 0
[time] => 1340792743
)
and i want to avoid those post where id is not 19 or like something. but my last query is not working :(, result is same.

Answer 1

It's because your logic is not mixing well with CodeIgniter's Active Record class. You cannot mix or_where and where or else you'll get fuzzy logic. You'll need to fix your logic in order for your query to be proper. Here's what I suggest.
Rewrite your foreach statements to pack everything into an array.
$ids = array();
foreach ($friend as $fr) {
foreach($fr as $f) {
if (...) {
$ids[] = $f->sub_id;
}
}
$this->db->where('time >', $f->time);
}
... And so on. When you're finished with your foreach statement, add the following line instead.
$this->db->where_in('user_id', $ids);
This should give you the ability to properly render your SQL statement with:
foreach($hide as $h)
{
$this->db->where('id !=', $h->post_id);
}