CODEWITHSUNDEEP
google-app-engine
zakdances
zakdances

Reputation: 23725

How to return any of the last Models added to the datastore?

How can I modify this

 videos = Video.gql( 'WHERE user_id = :1', '18' ).fetch(8)

so that instead of matching for a user_id, it returns any of the last 8 Video objects added to the datastore?

Upvotes: 2

Views: 174

Answers (3)

Eren Güven
Eren Güven

Reputation: 2374

You should save your models with a

created = db.DateTimeProperty(auto_now_add=True)

for this type of queries.

The accepted answer on this question is not correct. If you add a created property to your models and compare queries ordered by -created and -__key__ you will see that they don't match.

Keys that are automatically set will not be monotonically increasing. Some good read on that here .

Upvotes: 1

Jose Montes de Oca
Jose Montes de Oca

Reputation: 879

Another workaround would be to have a property that store the date created, this would allow you to query a bunch of different queries including last created.

Example

class Video(db.Model):
    ...
    user_id = ...
    date_created = db.DateTimeProperty(auto_now_add=True)
    ...

retrieve last 8 additions:

Video.all().order("-date_created").fetch(8)

Besides this, you can do more interesting queries by date range an so on.

Hope this helps as well!

Upvotes: 2

Attila O.
Attila O.

Reputation: 16625

Try this:

Video.gql('ORDER BY __key__ DESC').fetch(8)

In fact, you don't need to use GQL at all for this:

Video.all().order('-__key__').fetch(8)

Upvotes: 1

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