If that is the case, then your Abstract Entity Alpha scenario seems reasonable.
Steve On Nov 6, 2010, at 3:23 PM, Farrukh Ijaz wrote: > 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 <spe...@me.com> 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 >>> >>> >>> >>> _______________________________________________ >>> Do not post admin requests to the list. They will be ignored. >>> Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) >>> Help/Unsubscribe/Update your Subscription: >>> http://lists.apple.com/mailman/options/webobjects-dev/speery%40me.com >>> >>> This email sent to spe...@me.com >> _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
