Unable to define multiple primary keys

[alice-byb]

The Apollo Federation docs (and apollo-server), have a feature to define multiple primary keys. This allows different services resolve the entity by different fields. Here is the example from the Apollo docs:

type Product @key(fields: "upc") @key(fields: "sku") {
  upc: String!
  sku: String!
  price: String
}

Running this in ariadne (I am running 0.12.0), gives me the error: (the code to replicate is below)

TypeError: The directive 'key' can only be used once at this location.

In my case, I am happy to steer clear of this feature, however, our other microservices (running on Node) take advantage of this and there may come a time we want to take advantage of these types.

Code to replicate:

# schema file
from ariadne.contrib.federation import make_federated_schema

type_defs = """
type Query
type Mutation

type Product @key(fields: "upc") @key(fields: "sku") {
  upc: String!
  sku: String!
  price: String
}
"""

schema = make_federated_schema(type_defs)

...

# Flask server

@app.route("/graphql", methods=["POST"])
def graphql_server():
    # GraphQL queries are always sent as POST
    data = request.get_json()

    # Note: Passing the request to the context is optional.
    # In Flask, the current request is always accessible as flask.request
    success, result = graphql_sync(
        schema,
        data,
        context_value=request,
        debug=app.debug
    )

    status_code = 200 if success else 400
    return jsonify(result), status_code

[delyanr]

The graphql-js specs, which is what graphql-core is based off, do not allow repeatable directives on OBJECT. You can see this clearly in the following tests.

I suggest you use the following instead:

type Product @key(fields: "upc sku") {
  upc: String!
  sku: String!
  price: String
}

[mjfaga]

Hi there,

Wanted to check in on this despite it having been closed last year. The GQL spec does support repeatable directives, as outlined by this test.

For example, in a NodeJS federated implementation, the following SDL is valid, but this does not work currently in this library:

type Product @key(fields: "sku") @key(fields: "id") {
  id: ID!
  sku: String!
  price: String
}

Any chance you'd be willing to reconsider to support this functionality?

[sMorm]

Just want to add to this, repeatable is part of the graphql-spec that has been approved. Here is the (RFC) and the pre-release draft spec to show that repeatable is part of the specs.

Since Ariadne is built off of graphql-core v3, it seems like is_repeatable directives are already supported. With that said, I think that by adding repeatable to the Ariadne's base federation schema should allow for repeatable @key directives. I can create an issue and open a PR some time next week.

[rafalp]

I'm open to giving this another look.

Repo showing an example of this being done with apollo-servers federation would give us a head start.

[kuchichan]

Hello everyone,
I have prepared really tiny PR into Ariadne codebase, I have also prepared an example, that mimics apollo federation demo and behaviour described by tests in this PR (Similar issue in apollo-server). Details can be found in:
https://github.com/kuchichan/ariadne-federation-multiple-keys

[mjfaga]

Awesome, you beat me to it, thanks for getting that PR up!

[sMorm]

Hey @kuchichan — the federation specs has been updated to apply repeatable to the @key directive, hopefully that will help bolster your changes 😄