title: Hibernate: Mapping multiple classes to same table
body: <p>Consider a Transport table with 3 fields: Engine Wheels Wings</p>
  
  <p>If Engine and Wheels are non-null and Wings is null then I wish to map this to a Vehicle class
  If Engine and Wings are non-null and Wheels is null then I wish to map this to a Plane class</p>
  
  <p>I have been reading about discriminators to differentiate between subclasses but in any of the examples that I've read, they always refer to a discriminator value. Therefore, I'm wondering how I can go about my above scenario?
  Do I just implement separate mappings? I was hoping to find a neater way.</p>
  
  <p>Thanks</p>
  
  <p><strong>Edit</strong></p>
  
  <p>Have just looked through the reference guide again and have noticed that null and not-null are valid values. So looks like this solves my problem. Will leave this open for a little while to confirm. Thanks!</p>