高级搜索代码不会带来相关结果（Codeigniter）

I have written this CodeIgniter code for an advanced search. this advanced search has only a list of provinced for the uses to select from. But, I have problem, when searching, it brings results from other cities not selected by the user. Here is the code to match for the term:

$db->or_like("title", $_POST['search-term']); // OR 
$db->or_like("content", $_POST['search-term']);   // OR 
$db->or_like("name", $_POST['search-term']);    // OR   
$db->or_like("keywords", $_POST['search-term']);    // OR

And here is part of code responsible for matching with the selected province:

if(isset($_POST['province']) && $_POST['province'] != "0")
        { 
            $db->where("province", $_POST['province']); 
            if(isset($_POST['cities']) && $_POST['cities'] != "0")
            {
            $db->where("city", $_POST['cities']);   
            }
        } // AND    

And here is the code responsible for getting the data into an array:

$search_result = $db->get("ads")->result_array();

It is also worth mentioning that when I change the or_like to like it yields no result.

Here is the generated QUERY:

SELECT * FROM (`ads`) WHERE `status` = 2 AND `province` = '5' AND `title` LIKE '%شریف%' OR `content` LIKE '%شریف%' OR `name` LIKE '%شریف%' OR `keywords` LIKE '%شریف%' ORDER BY `stars` DESC

It seems to be sound and OK, but the results are not...

try this query then,

SELECT * FROM (`ads`) WHERE `status` = 2 AND `province` = '5' AND(
 `title` LIKE '%شریف%'
 OR `content` LIKE '%شریف%' OR `name` LIKE '%شریف%' OR `keywords` LIKE '%شریف%') 
ORDER BY `stars` DESC

Update: in CI you can try it like this:

$sql = "SELECT * FROM (`ads`) WHERE `status` = 2 AND `province` = '5' AND(
     `title` LIKE '%شریف%'
     OR `content` LIKE '%شریف%' OR `name` LIKE '%شریف%' OR `keywords` LIKE '%شریف%') 
    ORDER BY `stars` DESC";
$this->db->query($sql);

this would solve your problem.

Side Notes: your code is saying welcome to SQL injection. be aware of what you are doing.