Yes, they will expose certain properties which are symmetrical in all the 
entities, e.g. title, description, etc. 

Consider this requirement as a tree structure which can have nodes that appear 
to be symmetric but their underlying user object can be different.

Farrukh 

Sent from my iPhone

On 2010-11-06, at 9:58 PM, Steve Peery <[email protected]> wrote:

> Is there any shared functionality between Entity A, Entity B, Entity C and 
> Entity D that would justify Abstract Entity Alpha?
> 
> Steve
> 
> On Nov 6, 2010, at 7:39 AM, Farrukh Ijaz wrote:
> 
>> Hi EOF-ologists,
>> 
>> I've a modelling issue and need to know what could be the suitable fix (or 
>> tweak) to fulfil the requirement.
>> 
>> Below is the existing EO Model.
>> <Existing.png>
>> I've two entities (Entity A and Entity B) extending Abstract Entity X but 
>> these entities have their own tables (no single table inheritance). I need 
>> to design Entity D and Entity E where Entity D has a toMany relationship 
>> with Entity E and Entity E needs to have a toOne relationship with Entity A, 
>> Entity B, Entity C and Entity D. 
>> 
>> 1. One way can be for Entity E to have four different relationships such as 
>> toEntityA, toEntityB, toEntityC and toEntityD. (This is _not_ desirable)
>> 2. The other way mentioned in the lower diagram where Entity A, Entity B, 
>> Entity C and Entity D extend Abstract Entity X and Entity E will have toOne 
>> relationship with Abstract Entity X. (This is _desirable_).
>> <Desired.png>
>> What would be the easiest way to model such relationship? I'm _not_ 
>> relationship expert so may be the way I assumed the model (second diagram) 
>> can be wrong or practically impossible? 
>> Also note that I cannot make Entity C and Entity D to extend Abstract Entity 
>> X due to some design constraints therefore I think to introduce Abstract 
>> Entity Alpha.
>> 
>> Thanks,
>> 
>> Farrukh
>> 
>> 
>> 
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