Thank you all for answering and guiding me with the design. I wanted to know whether multiple tables can be part of a content provider. I have one database and my requirement is to share the DB across application and hence the Content Provider.
And after normalizing my tables, I realize a single content provider will be sufficient to handle all the tables in my db. Though I am struggling a little with URI matching concept, so trying some code like NoteList example. Once I run my own code, may be i will understand better. Thanks for the info, it help me a lot with the design. Regards, Arpit On Aug 24, 10:51 pm, "A. Elk" <[email protected]> wrote: > There are two considerations: database design and application design. > > Database design is much too big of a topic to summarize in a single > thread! But in short, one wants to normalize the data and do joins to > combine data from different tables. > > Application design in Android suggests that a ContentProvider isn't > necessary for private data. Basically, if you don't want to let other > applications look at your data (or modify it, or delete it) by > themselves, then you don't really need a ContentProvider. Of course, > you can have one if you want. You lose a bit of security, since the > data becomes "public", although you can keep pretty much private by > using an obscure URI. > > Also, it's best to have one database per ContentProvider. If you find > yourself trying to associate more than one database with the same > ContentProvider, your design may be suspect. Remember that a single > database can contain address data, book data, and people data, if the > domain is library management. On the other hand, you may choose to use > the built-in Contacts provider for people/address and your own > ContentProvider for books. > > In short, there's no one answer, except that you aren't limited to one > table per ContentProvider, one database per ContentProvider, or one > ContentProvider per Android application. A ContentProvider has some > overhead, but I'd opt for one per database rather than worry about the > overhead. > > On Aug 24, 9:17 am, Kostya Vasilyev <[email protected]> wrote: > > > > > A ContentProvider is queried (and updated) using a URI, which > > specifies the kind of data to work with. This might look like this: > > > content://<provider>/counties > > content://<provider>/counties/<country_id> > > > content//<provider>/counties/<country_id>/cities > > content//<provider>/counties/<country_id>/cities/<city_id> > > > Or even like this, in addition to the above: > > > content://<provider>/books > > content://<provider>/books/<book_id> > > > A helper class, UriMatcher, can be used in ContentProvider > > implementation to quickly and easily determine what kind of data a > > request URI refers to - whether it's counties, or cities, or a country > > by its id (in the examples above). > > > One the kind of data that the URI refers to is known, it's quite logical > > to store each kind of data in its own table (e.g. country / city). > > > I also think it makes sense to implement separate ContentProviders for > > unrelated sets of data. > > > In the example above, if you're not linking books to cities, you might have: > > > content://name.Arpit.GeographyData/counties > > content://name.Arpit.GeographyData/counties/1 > > content://name.Arpit.GeographyData/counties/1/cities > > > ...etc... and: > > > content://name.Arpit.Library/books > > content://name.Arpit.Library/books/1 > > content://name.Arpit.Library/books/2 > > > -- Kostya > > > 24.08.2010 20:01, Arpit пишет: > > > > Hi All, > > > > All the example codes, tutorials or video I see, there is always one > > > ContentProvider per SQL Table with the SQLiteOpenHelper extension > > > defined as a private static class... > > > > Is it some sort of standard design...to have one ContentProvider per > > > SQL Table? Or I can define one generic ContentProvider and use its > > > instance for ever update? > > > > Is there some issue with that? > > > > Could anyone please help as my application has like 5-6 tables. > > > > Regards, > > > Arpit > > > -- > > Kostya Vasilev -- WiFi Manager + pretty widget > > --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 [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
