Datastore - Support for OR predicate in GQL/Query Filters

[sai-pullabhotla]

Is there a reason why a datastore query (GQL or otherwise) does not allow OR predicate? I noticed that the AppEngine Datastore supports this -

(https://cloud.google.com/appengine/docs/java/javadoc/com/google/appengine/api/datastore/Query.CompositeFilter).

I was under the impression that Cloud Datastore is similar (or same) as AppEngine Datastore.

In any case, is this some thing that can be supported?

[mziccard]

@aozarov @ajkannan Any reason we don't support OR?

[ajkannan]

It looks like "OR" isn't supported in Cloud Datastore yet.

Looking at the current cloud docs and previous cloud docs, I don't see "or" mentioned under composite filter operators, just "and". Also, this page and this page (in the "where" row) affirm that only "and" is supported for now.

/cc @eddavisson are there plans to support "OR" in Cloud Datastore?

[sai-pullabhotla]

@ajkannan - This page clearly states that -

Restrictions on queries

The nature of the index query mechanism imposes certain restrictions on what a query can do. Cloud Datastore queries do not support substring matches, case-insensitive matches, or so-called full-text search. The NOT, OR, and != operators are not natively supported, but some client libraries may add support on top of Cloud Datastore.

I wonder if any of the client libraries (possibly Python or the AppEngine Java API) do this, and if so, how do they do it? Something to look into.

[mziccard]

@sai-pullabhotla I can confirm that OR is not supported natively. And yes, some clients (AppEngine SDK and python ndb) support OR by issuing multiple queries and then merging the results. Such a feature is out of the scope of our client which is meant to be a java-idiomatic but thin layer on top of Datastore API. AFAIK none of the other google-cloud-* libraries supports OR.

[sai-pullabhotla]

@mziccard - Thanks. I just wanted to make sure if this is something the Datastore supports or not. Now we know the answer. I'm closing this.