Hi Markus,
On Sun, Sep 20, 2009 at 10:01 PM, Markus <[email protected]> wrote:
>
> Hello,
>
> I have two db.Models let's call it Model A and Model B.
>
> Model B has an field "ref = db.ReferenceProperty(A)"
>
> Now I know a db.key from a database entry in A and want to find all
> database entries of B which referes to that specific entry in A.
>
> I tried a naive approach:
>
> # first get all entries from B
> datas = db.GqlQuery("SELECT * FROM B")
>
> #
> for B in data:
> # if B.ref == familarKeyFromA:
>
B.ref is an Entity, not a key, so hence the comparison will always fail.
> # found an entry in B who referes to A
> ...
>
> But this doesn't work. I get no results. But i know that there exists
> entries in B with a reference to an entry in A (familarKeyFromA).
>
> Probably the simple "if B.ref == familarKeyFromA" doesn't work. But
> how can I compare to db.key's?
>
You can simply query for entities whose keys match: db.GqlQuery("SELECT *
FROM B WHERE ref = :1", somekey).
-Nick Johnson
>
> Thanks a lot!
> >
>
--
Nick Johnson, Developer Programs Engineer, App Engine
Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number:
368047
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