none
Need help for the query

    คำถาม

  • Hi,

     

    I have the following tables in my data base with following columns:

     

    Table 1(Water_Usage_per_hour): user_id, water_used_per_hour, Update_time (when data updated)

    Table 2(User_info): user_id, locality, state

     

    There are two applications interacting with this database:

    Application 1: it updates the data of different users at different instant of time. We believe that different users started using the application at different times therefore their hourly updation will also differ

    Application 2: this does the following query->

     

    it gets the total water used every hour by the users belonging to a particular locality ( say 'a' ) for the last 6 hours ie

    total water used by all users of locality 'a' in last hour, total water used by all users of locality a in hour before last and so on.

     

    can any body help us with the possible query of the 2nd application ???

    3 กุมภาพันธ์ 2555 15:29

คำตอบ