Hi,
I´ve come with a solution to a similar problem I had.
What I did was this:
Lets say you can have MAX 6 rooms, so, on one field you store the
actual number of rooms and in other a list of "room queries" que
entity fits:
I'll explain myself:
class Entity{
Long rooms;
ArrayList<Long> roomQueries;
}
Now you need a code for every possible query for a room range i.e.
"14" (from 1 to 4), "23" (from 2 to 3), "1" (exactly 1). Then you
calculate the ranges that fit your number of rooms and store them in
"roomQueries".
Having all this set, you can query with a equality filter
i.e .filter(roomQueries = 56).
Another way of implementing this (actually the one im using) is
assigning every "slot" a power of 2, then a range query would be the
sum of all "slots" values involved
Using the above case, you'd have
1 room -- > 1
2 rooms -- > 2
3 rooms -- > 4
4 rooms -- > 8
5 rooms -- > 16
6 rooms -- > 32
the the query for 2 to 3 rooms would be = 6, 2 to 5 = 30.. and so on.
Hope this can help you :)
On Sep 19, 2:11 am, "GAE-framework.googlecode.com"
<[email protected]> wrote:
> Hillo GAE developers!
>
> I have a serious situation with datastore. I need select data from
> model with multiple criteria. I have a House model, where exists
> fields: cost, rooms, floor. I need filter all houses, where cost >
> 50000 and < 150000, and also rooms > = 3 and < 5, and also floor >= 1
> and < 3.
>
> How can I select this dataset? As I see, the Datastore says that I can
> use filter criteria with >, <, >=, <= and != only on one column. But I
> reallly need use this rules on multiple columns.
>
> Please, help me!!!
> How to implement my task with Datastore limitations?
>
> Thank you. I really need your help.
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