On Aug 23, 2010, at 11:06 AM, Amy Heavey wrote: > Hi, > > I've got a core data app that I'm working on, and I started off with quite > simple relationships. I've got a products entity, and a purchase order > entity, which had many to m any relationships between them. I now need to be > able to set a quantity for each product in each purchase order. I think I > need to set up an inbetween entity, (called purchaseOrderItem) which stores > the quantity for each product, and has relationships to the product and > purchase order entity. > > I can set it all up in the datamodel, but to be able to use the data already > in the app I need to migrate it over. I expect to initially set all quantites > to 1, but I can't work out how to set up the mapping model so it moves the > relationships correctly. > > Can anyone point me in the right direction? > > data model 1.0 > Entities: Product, PurchaseOrder > Relationships: Product <<---->>PurchaseOrder > > data model 1.1 > Entities: Product, PurchaseOrder, PurchaseOrderItem > Relationships: Product <---->> PurchaseOrderItem > PurchaseOrderItem <<----> PurchaseOrder
I wouldn't change the existing relationship(s)--create new ones instead. You will have to subclass NSEntityMigrationPolicy to create appropriate "PurchaseOrderItem" relationships from the "Product" relationships. Have you read this doc: http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/CoreDataVersioning/Articles/vmMigrationProcess.html#//apple_ref/doc/uid/TP40005508-SW4 ? HTH, Keary Suska Esoteritech, Inc. "Demystifying technology for your home or business" _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
