I have a one to many relationship between two objects, lets call them Gallery and Images.
Each Image belongs to a Gallery and each Gallery has many Images.
I would like to add a fetched property to my Gallery model which would return one and only one Image object.
Is there a way to do this with fetched properties?
For a fetched property, a predicate is your only option.
See the Predicate Programming Guide – Aggregate Operations section. You’ll want to use
array[FIRST].Note, you’ll likely get a different image each time, since there is no support for ordered sets in Core Data. You’d normally get around this by maintaining your Images’ sort order in a “sortOrder” key and setting sort descriptors on your fetch, but I don’t think it’s possible to give sort descriptors on a fetched property.
Update for Lion: Support for ordered sets has been added to Core Data in 10.7 and above, making an extra “sortOrder” attribute unnecessary for apps targeting 10.7 and up.