> I'm aware that the datastore isn't a relational database and as such
> doesn't support many relational database features.

> I'm wanting to create a street address lookup with a model something
> like this;

> class Address(db.Model):
>         street = db.StringProperty()
>         suburb = db.StringProperty()
>         postcode = db.StringProperty()
>         city = db.StringProperty()
>         lon = db.StringProperty()
>         lat = db.StringProperty()

> The thing I'm trying to get my head around is how to query for results
> with a partial address i.e. "For" returning ("Forest Street", "Forman
> Avenue", ...).

> Normally one could do this with a LIKE condition (SELECT * FROM
> address WHERE street LIKE 'For%'). I'm not sure how I would go about
> this using the datastore since it only supports the common comparison
> operators.

> Does anyone have any insights on how to achieve this end result in
> some way using the datastore?

> Many thanks,

> hads

>  Hi all,

>  I'm aware that the datastore isn't a relational database and as such
>  doesn't support many relational database features.

>  I'm wanting to create a street address lookup with a model something
>  like this;

>  class Address(db.Model):
>         street = db.StringProperty()
>         suburb = db.StringProperty()
>         postcode = db.StringProperty()
>         city = db.StringProperty()
>         lon = db.StringProperty()
>         lat = db.StringProperty()

>  The thing I'm trying to get my head around is how to query for results
>  with a partial address i.e. "For" returning ("Forest Street", "Forman
>  Avenue", ...).

>  Normally one could do this with a LIKE condition (SELECT * FROM
>  address WHERE street LIKE 'For%'). I'm not sure how I would go about
>  this using the datastore since it only supports the common comparison
>  operators.

>  Does anyone have any insights on how to achieve this end result in
>  some way using the datastore?

>  Many thanks,

>  hads

> http://en.wikipedia.org/wiki/Trie

>  On Apr 13, 8:24 pm, "Brett Morgan" <brett.mor...@gmail.com> wrote:
>  > I'd probably head down the path of maintaining a trie for all the
>  > words in the fields you want partial search on. This would give you
>  > the ability to do ajax drop down completion on the fields after two or
>  > three characters.

>  > http://en.wikipedia.org/wiki/Trie

>  Thanks Brett, that's one idea I had thought of and I guess the only
>  real solution.

>  Hubert, unfortunately that wouldn't work in this situation. For one
>  the data set is far too large (every street name in the country) to
>  process like that and secondly it would be over the limits of the
>  datastore api.

>  Cheers,

>  hads

>  On Apr 13, 8:50 pm, "Brett Morgan" <brett.mor...@gmail.com> wrote:
>  > What i'd think would be a first approximation, given your dataset
>  > size, would be to start the trie at something like three characters,
>  > and have a seperate datastore entity for each of those start nodes.

>  That's my thought too.

>  > I suspect you are going to have to precompute the trie on your desktop
>  > and bulk upload it tho.

>  Yeah. I'm currently playing with the comparison operators after
>  finding a tip on the following page (I thought I'd read all the docs -
>  must have missed that bit);

>  http://code.google.com/appengine/docs/datastore/queriesandindexes.html

>  This may be an easier route.

>  On Apr 13, 9:03 pm, "Brett Morgan" <brett.mor...@gmail.com> wrote:
>  > I don't see how comparison operators help with partial word matching.
>  > Please tell us how it works out. =)

>  Confused me for a minute too :)

>  The tip on that page is at the bottom of the "Introducing Indexes"
>  section.

>  I'm currently using something like this;

>  q = 'For'
>  addresses = db.GqlQuery('SELECT * FROM Address WHERE street >= :1 AND
>  street < :2', q, q + 'z')

>  which works fine. Now all I need to do is store a lowercase name with
>  every entity.