GRR. I think I understand now what you mean.. Migrations its complaining whe trying to create that specific table Area which has a relationship with itselfs...
it creates all of the rest. except that one, saying that I have a mysql syntax error. which I guess I don't what to do :( On Tue, Aug 11, 2009 at 1:27 PM, Gustavo Pizano <[email protected]>wrote: > Hello david... UUFFFF my life gets better htne because Im using Mysql. > > On Tue, Aug 11, 2009 at 1:16 PM, David Avendasora < > [email protected]> wrote: > >> >> On Aug 11, 2009, at 7:05 AM, Gustavo Pizano wrote: >> >> Hello Dave. >> >> It does have only one parent. >> >> >> Well that's good. It makes your life much easier. >> >> What database are you using for this project? Keep in mind that WO doesn't >> insert objects into the database in the same order in which you may have >> created them, so it is entirely possible for WO to try to insert a "Sub >> Area" before it's "Parent Area" is inserted. Most DBs handle this situation >> by allowing you to defer constraints, which is handled automatically for you >> by the WO DB plugin. Microsoft SQLServer however does not have deferred >> constraints and the DB plugin doesn't handle this specific situation, so if >> you are using SQLServer, be careful with self-referential relationships. >> >> Dave >> >> >> >> On Tue, Aug 11, 2009 at 1:02 PM, David Avendasora < >> [email protected]> wrote: >> >>> >>> On Aug 11, 2009, at 6:21 AM, Gustavo Pizano wrote: >>> >>> Hello Im doing an eomodel.. .and I have an entity called Area, and >>>> SubArea, for me an area can have many subareas, but subarea its an area >>>> itself also.. >>>> so its like Area <- >>SubArea. >>>> >>> >>> If a SubArea is really just an Area with a parent, then I'd just have one >>> Entity of Area with an optional to-one relationship to parent. >>> >>> I'd model it as Area <->> Area with Area having a foreign key that >>> points to the PK. You'll end up with each Area having a parentArea and >>> multiple subAreas. >>> >>> This assumes that an Area can have only one parent. If an Area can have >>> more than one parent, then you'll need a many-to-many join. >>> >>> Dave >>> >>> >>> >>>> Now what are the implications of defyning Area with its properties, and >>>> then SubArea and put as parent Area?... I see that inside Area Entity there >>>> is SubArea Entity also... but I guess this doesn't guaranties me the >>>> to-many >>>> relationship between the 2 entities isn't it?do I still have t defying the >>>> relationship? >>>> >>>> >>>> Thanks >>>> >>>> Gustavo >>>> >>>> _______________________________________________ >>>> Do not post admin requests to the list. They will be ignored. >>>> Webobjects-dev mailing list ([email protected]) >>>> Help/Unsubscribe/Update your Subscription: >>>> >>>> http://lists.apple.com/mailman/options/webobjects-dev/webobjects%40avendasora.com >>>> >>>> This email sent to [email protected] >>>> >>> >>> >> >> >
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