It's not clear to me why you need a join here. If you're just doing it by Department type, why not make the "Department" field a String?
Ikai Lan Developer Programs Engineer, Google App Engine Blog: http://googleappengine.blogspot.com Twitter: http://twitter.com/app_engine Reddit: http://www.reddit.com/r/appengine On Thu, Jun 16, 2011 at 3:30 PM, Bruce Aloe <[email protected]> wrote: > Hello, > > In a simple case, suppose i have two kinds (tables) stored in GAE > datastore: > > Employee (EmployeeId, Name, Salary, StartDate, DepartmentId) > Department(DepartmentId, DepartmentName) > > For Employee kind, EmployeeId is the unique key and DepartmentId is > the join attribute for Employee to make join with Department kind. For > Department kind, DepartmentId is the unique key. Both Employee and > Department kinds have quite a lot of tuples, let us say, more than 3 > million tuples. > > There is a need to make join query over both Employee and Department > kinds in order to answer the query concerns the data from both kinds. > For example a query could be "List all employees's Id, name, salary > and their department name for the ones earns more than 8000 US > dollar". > > How can i make join query among different kinds to answer the query > concerns different kinds? > > Of course, there could be more than just two kinds stored in GAE > datastore. If one wants to make join query among more than two kinds, > how to handle that? > > Thank you for your help! > > Bruce > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" 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/google-appengine?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" 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/google-appengine?hl=en.
