title: Code igniter prepending db prefix in table aliases
body: <p>I have configured code igniter to use db prefix.</p>
  
  <p>At all other places it is working as expected but while creating table aliases it is prepending db prefix.</p>
  
  <p>Code is as under:-</p>
  
  <pre><code>$this-&gt;db-&gt;from('table_a');
  $this-&gt;db-&gt;join('table_b', 'table_a.id = table_b.a_id', 'left');
  -----
  $this-&gt;db-&gt;join('table_b as tablebAlias', 'table_c.id = tablebAlias.a_id', 'left');
  </code></pre>
  
  <p>Assuming my dbprefix is set to value 'foo'.</p>
  
  <p>Final query which is getting executed is as under:-</p>
  
  <pre><code>Select * From foo_table_a left join foo_table_b on foo_table_a.id = foo_table_b.a_id
  --- left join foo_table_b as tablebAlias on foo_table_c.id = foo_tablebAlias.a_id
  </code></pre>
  
  <p>Any help will be highly appreciable.</p>
  
  <p>Thanks,
  Jatin</p>