why cant my NPE have a 1-1 to a PE?

im guessing there is some technical reason for this?   1 to 1 is going to save me using lots of getting the list, and then doing the list get first element etc...  
1 answers

Hi Jason,


This is because by setting the association as 1-1, you are essentially setting both entities as the owner of the association (see One-to-One Association):

"A one-to-one association is created by setting the owner property to Both"


No such thing is allowed between a NPE and a PE, because that would mean that the association could start from the PE, and when the NPE entity "dissappears", the PE will no longer know where to find it.


I hope that solved your question, best regards!