Mechanism for turning nested JSON into foreign keys / many-to-many

The GitHub JSON APIs have a really interesting convention with respect to related objects.

Consider https://api.github.com/repos/simonw/sqlite-utils/issues - here’s a truncated subset:

  {
    "id": 449818897,
    "node_id": "MDU6SXNzdWU0NDk4MTg4OTc=",
    "number": 24,
    "title": "Additional Column Constraints?",
    "user": {
      "login": "IgnoredAmbience",
      "id": 98555,
      "node_id": "MDQ6VXNlcjk4NTU1",
      "avatar_url": "https://avatars0.githubusercontent.com/u/98555?v=4",
      "gravatar_id": ""
    },
    "labels": [
      {
        "id": 993377884,
        "node_id": "MDU6TGFiZWw5OTMzNzc4ODQ=",
        "url": "https://api.github.com/repos/simonw/sqlite-utils/labels/enhancement",
        "name": "enhancement",
        "color": "a2eeef",
        "default": true
      }
    ],
    "state": "open"
  }

The user column lists a complete user. The labels column has a list of labels.

Since both user and label have populated id field this is actually enough information for us to create records for them AND set up the corresponding foreign key (for user) and m2m relationships (for labels).

It would be really neat if sqlite-utils had some kind of mechanism for correctly processing these kind of patterns.

Thanks to jq there’s not much need for extra customization of the shape here - if we support a narrowly defined structure users can use jq to reshape arbitrary JSON to match.

[simonw]

So maybe something like this:

curl https://api.github.com/repos/simonw/datasette/pulls?state=all | \
  sqlite-utils insert git.db pulls - \
    --flatten=base \
    --flatten=head \
    --extract=user:users:id \
    --extract=head_repo.license:licenses:key \
    --extract=head_repo.owner:users \
    --extract=head_repo
    --extract=base_repo.license:licenses:key \
    --extract=base_repo.owner:users \
    --extract=base_repo

Is the order of those nested --extract lines significant I wonder? It would be nice if the order didn’t matter and the code figured out the right execution plan on its own.

[izzues]

Have you seen MakeTypes? Not the exact same thing but it may be relevant.

And it’s inspired by the paper “Types from Data: Making Structured Data First-Class Citizens in F#”.