title: Active record to select row from two table from specific condition
body: <p>I want to select rows from two table using specific condition in code igniter.</p>
  
  <p>I used this code.But its not working. Please help me.</p>
  
  <pre><code> $this-&gt;db-&gt;select('*');
   $this-&gt;db-&gt;from('post_response');
   $this-&gt;db-&gt;where('post_response.user_id', $response_id);  //$repsonse_id has value from contoller
   $this-&gt;db-&gt;join('register','register.id = post_response.user_id'); 
   $query = $this-&gt;db-&gt;get();
   return $query-&gt;result();
  </code></pre>
  
  <p>I have value in these tables but this return an empty array. </p>
  
  <p>Tables:</p>
  
  <h2>Post_reponse</h2>
  
  <p>user_id | message</p>
  
  <p>18      | something</p>
  
  <h2>register</h2>
  
  <p>id | name |</p>
  
  <p>18 | john |</p>
  
  <h2>Output should be:</h2>
  
  <p>id | message  | name</p>
  
  <p>18 | somthing | john</p>