> I'd assumed that the length of a db.Model instance's db.Key().name()
> was a constant plus a linear function of the depth the entity in its
> entity group.]
As I wrote above, I should have said length of str(db.Key() instance).
db.Key's __str__ definition on google/appengine/api/
datastore_types.py, line 404 says
Unfortunately, this string encoding isn't particularly compact,
and its
length varies with the length of the path. If you want a shorter
identifier
and you know the kind and parent (if any) ahead of time, consider
using just
the entity's id or name.
On Oct 15, 9:12 pm, Andy Freeman <[EMAIL PROTECTED]> wrote:
> I'm not using entity groups (in this case) because the entity/db.Model
> instance that I'm constructing doesn't have a reasonable ancestor.
> There will be too many of them to put under any of the db.Model
> instances that I'm using to build the key_name, let alone to put under
> a single root.
>
> The db.Model instance that I'm creating will not be used to create
> other keys. The other db.Model instances whose Keys() I want to use
> to create the key_name are likewise either root entities or at a very
> short depth in an entity dag.
>
> I'd assumed that the length of a db.Model instance's db.Key().name()
> was a constant plus a linear function of the depth the entity in its
> entity group.
>
> If my assumption is true, the key_names that I'm planning to construct
> will have bounded length. If the db.Key() s constructed by the dev
> environment are the same length as those in the production
> environment, I should be able to figure out whether said bounded
> length is less than the max length of a key_name.
>
> On Oct 15, 2:19 pm, "Marzia Niccolai" <[EMAIL PROTECTED]> wrote:
>
>
>
> > Hi Andy,
>
> > I believe there is a limit on key names of 500 bytes, but I can't seem to
> > find it in the documentation.
>
> > I think the question I have is there a reason you are not using entity
> > groups? When using entity groups you can use Key.from_path() to construct
> > key objects from the ancestor
> > path:http://code.google.com/appengine/docs/datastore/keyclass.html#Key_fro...
>
> > This way you don't need to build up longer and longer key names.
>
> > -Marzia
>
> > On Wed, Oct 15, 2008 at 2:03 PM, Andy Freeman <[EMAIL PROTECTED]> wrote:
>
> > > I'd like to construct a key_name (for get_or_insert) by concatenating
> > > the name() s of a couple of db.Key s.- Hide quoted text -
>
> > - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"Google App Engine" group.
To post to this group, send email to google-appengine@googlegroups.com
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
-~----------~----~----~----~------~----~------~--~---
