• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: Qualifiers, many-to-many and horizontal inheritance
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Qualifiers, many-to-many and horizontal inheritance


  • Subject: Re: Qualifiers, many-to-many and horizontal inheritance
  • From: Chuck Hill <email@hidden>
  • Date: Fri, 21 Jul 2006 15:03:42 -0700

You pretty much have to use some sort of extension to the qualifiers that ship with WO. It looks like Pierre Bernard has posted updated versions of his here:
http://www.bernard-web.com/pierre/webobjects/code.html


I use these and they are excellent!

Chuck


On Jul 21, 2006, at 2:39 PM, Timo Hoepfner wrote:

Hi,

I have some entity (Asset, representing files with added meta info) which has a many-to-many relationship to an abstract entity (Keyword) in a horizontal inheritance scheme (subclasses are very heterogenous. All they have in common is a "name" attribute).
Navigating through the object graph works fine, but I have some problem figuring out how to build qualifiers that do what I want. I want to build qualifiers that match


1. Any Asset which has a certain filename
2. All Assets that have no associated Keyword and have a certain filename
3. All Assets that belong to a certain Keyword and have a certain filename
4. All Assets that belong to any Keyword in a given list of Keywords and have a certain filename (Some of the concrete Keyword subclasses build a tree and I want to match Assets belonging to a certain Keyword and all of its children)


1. is trivial
2. I've built a FetchSpec utilizing raw SQL, which does the "no associated" keyword stuff, but I have no clue how to pass bindings to a FetschSpec when using raw SQL (to get the "match filename" stuff)
3. Can be done easily by navigating via asset.keywords, but I'd like to build a qualifier to be able to restrict by other attributes, too (w/o doing in-memory filtering). I haven't been able to build an EOQualifier (w/o raw sql) which does that. I think there should be a way... In most cases I get either NPEs, CCEs or SQL-Exceptions, because the generated SQL tries to look into tables which don't exist (abstract), etc. I also tried to use some of the Wonder qualifiers, but no luck so far.
4. Basically the same situation as 3.


I'd be more than thankful for a bit of help!

Timo



_______________________________________________
Do not post admin requests to the list. They will be ignored.
Webobjects-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40global-village.net


This email sent to email@hidden

--
Coming sometime... - an introduction to web applications using WebObjects and Xcode http://www.global-village.net/wointro


Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects




_______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (email@hidden) Help/Unsubscribe/Update your Subscription: This email sent to email@hidden
  • Follow-Ups:
    • Re: Qualifiers, many-to-many and horizontal inheritance
      • From: Timo Hoepfner <email@hidden>
    • Re: Qualifiers, many-to-many and horizontal inheritance
      • From: Timo Hoepfner <email@hidden>
References: 
 >Qualifiers, many-to-many and horizontal inheritance (From: Timo Hoepfner <email@hidden>)

  • Prev by Date: Re: WWDC Security concern
  • Next by Date: Re: WWDC Security concern
  • Previous by thread: Qualifiers, many-to-many and horizontal inheritance
  • Next by thread: Re: Qualifiers, many-to-many and horizontal inheritance
  • Index(es):
    • Date
    • Thread