The important thing is to have the results returned in a way that the data doesn't need to all be loaded up-front in order to do the join, like CursorJoiner does. This has significant limitations on how you can do the joins.
On Thu, Mar 10, 2011 at 4:04 PM, Jay <johnabloodwor...@gmail.com> wrote: > Thank you for your reply. I do know that there is no requirement for > ContentProviders to map URIs one-to-one to tables. To clarify, I am > asking about the case where the ContentProvider and the joined DB are > in separate applications, so the join can't be done within the SQLite > engine. The CursorJoiner class you reference seems to be designed for > exactly what I am talking about, but I would still appreciate any > insights anyone has in making a manual join like this efficient. > > Thanks again, > Jay > > On Mar 10, 3:07 pm, Kostya Vasilyev <kmans...@gmail.com> wrote: > > Not sure I understand the question: the implementation of a > > ContentProvider doesn't have to map data URIs to one particular table > each. > > > > It's probably the most obvious thing to do, but it doesn't have to be > > this way. You can map URIs to DB queries any way you like, and include > > JOIN's if needed (just use db.rawQuery for this). > > > > And then there is: > > > > http://developer.android.com/reference/android/database/CursorJoiner.... > > > > if you need to do the join yourself. Which is just a simple helper class > > that makes joins more efficient by requiring that both result sets (left > > & right) are sorted. > > > > -- Kostya > > > > 10.03.2011 22:40, Jay Bloodworth пишет: > > > > > Is there a standard or recommended idiom for doing the equivalent of a > > > join of data in a local database versus a content provider? is there > > > anything more efficient than explicitly looping on the result set from > > > the local database query and doing individual queries of the content > > > provider to grab the related rows? > > > > > Jay > > > > -- > > Kostya Vasilyev --http://kmansoft.wordpress.com > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to android-developers@googlegroups.com > To unsubscribe from this group, send email to > android-developers+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- Dianne Hackborn Android framework engineer hack...@android.com Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails. All such questions should be posted on public forums, where I and others can see and answer them. -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
