title: Laravel merge Relationship
body: <p>I have 2 tables <code>bookings</code> and <code>eventDates</code>.</p>
  
  <p><code>bookings</code> table has 2 fields <code>checkIndate</code> and <code>checkOutDate</code> which points to <code>eventDates</code> table.</p>
  
  <p>I setup following relationships</p>
  
  <pre><code>public function eventCheckInDate() {
      return $this-&gt;belongsTo( 'EventDate', 'checkInDate' );
  }
  public function eventCheckOutDate() {
      return $this-&gt;belongsTo( 'EventDate', 'checkOutDate' );
  }
  </code></pre>
  
  <p>How can I combine those relationship so that eloquent only runs single query and get the data?</p>
  
  <p>What happens now is it run 2 queries even if <code>checkInDate</code> and <code>checkOutDate</code> are still the same.</p>
  
  <p>Thank you</p>