title: GreenDao primary key on multiple columns
body: <p>I am using greendao to maintain SQL database on Android. Right now I am facing a problem of generating entity with two columns as primary key. To be clear I have column1 and column2 both of them are Long values and they together form a primary key.</p>
  
  <p>I tried to model it as</p>
  
  <pre><code>@Index(unique = true)
  private Long column1, column2
  </code></pre>
  
  <p>but it is not working. I am getting unique constrain failed when trying to insert and when trying to inserOrReplace it simply replaces based on column1 id.</p>