I' curious if Mendix fully supports many to many recurisive relationships? The data modeler allows creating a many to many association from Entity A to Entity A. Let's call this association A_A. Let's say I've created two instances of A - A1 & A2. When I associate A2 to A1 the reference set for A1 seems to accurately reflect the member of A2 over the A_A association. However, when I go to look at A2, its A_A association reference set is empty. It's as if system does not truly treat the A_A association as a many to many. Is this an implementation short coming within Mx? I've noted that on the A_A properties, the modeler complains if the Owner property is set to "Both". The error message states: Owner must be "Default" for self-referential associations. Am I missing something, or is this a limitation within Mx? I could get around it with an old fashioned associative entity, but would rather not go that route unless I have to.
From my experience with mendix n:m self associations i'd say: don't do it; or have a really good reason.
retrieve by association only works one way (at least without java)
reversed() will give you headaches, and everyone else who is trying to bugfix your retrieves. too (and it still had issues 'till 7.3)
quite often you need some attribute on the association later on anyway.
A1 referencing A2 is not the same as A2 referencing A1. That's why owner:both is not possible here.
Mendix suppport this, but you may need to use the reversed() function in your XPath retrieves, as detailed here.