On Wed, Mar 8, 2017 at 3:48 AM, Aristedes Maniatis <a...@maniatis.org> wrote: > On 7/3/17 11:12pm, Nikita Timofeev wrote: >> 2) Add new factory methods in Property class: >> >> <T extends Persistent> Property<T> createSelf(Class<? super T> type); > > Why wouldn't we just use normal constructors? > > a = new Property(Artist.class);
That's because createSelf() method will create expression needed for this to work. And as mentioned in the first mail this new expression can later be used in other ways. > >> <T extends Persistent> Property<T> createForRelationship( >> Property<?> property, Class<? super T> type) > >> 3) Prohibit direct usages of properties mapped on toMany >> relationships, so that the following code will throw a >> CayenneRuntimeException >> >> List<Object[]> result = ObjectSelect.query(Artist.class) >> .columns(Artist.ARTIST_NAME, Artist.PAINTING_ARRAY) >> .select(context); > > I'm confused about why we need a new type of property for this rather than > just using Artist.PAINTING_ARRAY > This is because PAINTING_ARRAY have List<Painting> type and we currently can provide only Painting. So to have proper type we need another Property to be created. Thou it is indeed a question whether we need this at all: a ColumnSelect result as it will be is raw SQL, i.e. in this example Paintings not folded into a List. For me it's not clear when do we need direct List result for toMany relationship instead of using Prefetch (or even selecting related entities explicitly). -- Best regards, Nikita Timofeev
