Re: Attempt to insert null key into a com.webobjects.foundation.NSMutableDictionary
Re: Attempt to insert null key into a com.webobjects.foundation.NSMutableDictionary
- Subject: Re: Attempt to insert null key into a com.webobjects.foundation.NSMutableDictionary
- From: email@hidden
- Date: Thu, 15 May 2003 17:28:30 +0100
Jevon,
On Thursday, May 15, 2003, at 03:28 pm, Jevon Hills wrote:
Now for more of how I'm confused. I probably did not state at the
beginning that I'm working using a corporate database, which is not
only used for WO, but by several different tools. As a result I the
relation ship of CollectionDesc<-->>Collection<<-->Content is that of
3 tables which I have to use/maintain.
So having followed your instructions I have the following questions:
Can I get CollectionDescContent entity that EOModeler created to
maintain the table of Collection for me?
Yes you can. Inspect the entity CollectionDescContent and rename the
table and the properties as required.
As far as terminology, can you direct me to a good source on the Web
which can help me better understand 'Properties' and other elements of
WO? Up until now I assumed, and it appears incorrectly, that
Properties were synonymous with "Attributes", "Member Data", "Fields"
(.NET lingo).
The difference is that there is not a 1-to-1 mapping between properties
and data fields. You can define properties that don't exist in the
database (e.g. flattened relationship), and there can be data fields
that are not reflected in the model. Same thing for entities vs tables.
The whole point of the model is to abstract your application from the
underlying database scheme, so that you can change the database without
changing your code (in principle).
As far as reference materials that I have on hand: WebObjects
Developer's Guide by Ravi Mendis, Building WebObjects 5 Applications
by Jesse Feiler, Professional WO 5 (Wrox Press). Are there any others
you would recommend?
Nothing replaces personal experience :-)
(I will let others suggest good books)
-- Denis.
_______________________________________________
webobjects-dev mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/webobjects-dev
Do not post admin requests to the list. They will be ignored.