codeigniter read table and field metadata

ci_table_field_metadata

function readDB()
{
		$tables = $this->db->list_tables();
		foreach($tables as $table){
			$query = $this->db->field_data($table); 
			echo '<h5>'.$table.'</h5>';
			echo '<ul>';
			foreach ($query as $field)
			{
				echo '<li>'.$field->name.' - '.$field->type.' '.($field->primary_key ? '- <b>primary</b>':''). '</li>';
			}		
			echo '</ul>';	
		}
		exit;
}