On Fri, Nov 12, 2010 at 10:52 AM, pramod.deore <[email protected]> wrote: > Hi, Kostya Thanks. But I think it only override older value. what I > want is > > If suppose I have > roomid:101 > roomName:Hall > switchid:202 > switchName:AC > > Now if suppose I insert a record as(101,Hall,203, Light) > > then record is added as > roomid:101 > roomName:Hall > switchid:202,203 > switchName:AC,Light. > > I hope you understand what I am trying to say. >
Pramod, to achieve the above you will need to change your data model. It is obvious that in your case each room can have multiple switches. By storing this data in the ROOM table, you are breaking few rules.(*) Create separate table for switches and additional table that maps from roomid -> switchid Then to "add" extra switches to a room, you either insert new switch into switch table or just search for switchid, if added switch already exists in your data and then add it to this table that achieves 1 to many mapping between roomid and switchid. You have to have a look at data modelling and '1 to many' relationships between entities. (*) we are talking data normalisation and various forms of this; By normalising your data, you will improve consistency and reduce duplication, but retrieval will cost you more time, since it will rely on JOIN operations. This is not too optimised in SQLite... You will have to make few judgement calls, but it will be dependant on your particular problem. -- Daniel Drozdzewski -- 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
