How to fix index error when querying GAE datastore?

Question

When I try to run a query on the datastore ordered by date I get the following error:

NeedIndexError: no matching index found.
The suggested index for this q         


        

Answer 1

You need to specify the "direction" as well because "ordering" is done when index is written to speed things up in Google's style.

So, your index.yaml should be like:

indexes:

- kind: Message
  properties:
  - name: author
  - name: ref
  - name: date
    direction: desc

Here's Google's official description about order:

The direction to sort, either asc for ascending or desc for descending. This is only required for properties used in sort orders of the query, and must match the direction used by the query. The default is asc.

I hope this helps.