datasette-graphql 0.2

A GraphQL endpoint for Datasette

datasette-graphql

A GraphQL endpoint for Datasette

Work in progress alpha - this has many missing features.

Try out a live demo at datasette-graphql-demo.datasette.io/graphql.

Installation

Install this plugin in the same environment as Datasette.

$ pip install datasette-graphql

Usage

This plugin sets up /graphql as a GraphQL endpoint for the first attached database.

Querying for tables and columns

Individual tables can be queried like this:

{
  repos {
    nodes {
      id
      full_name
      description
    }
  }
}

Accessing nested objects

If a column is a foreign key to another table, you can request columns of that table using a nested query like this:

{
  repos {
    nodes {
      id
      full_name
      owner {
        id
        login
      }
    }
  }
}

Filtering tables

You can filter the rows returned for a specific table using the filters: argument. This accepts a list of filters, where a filter is a string of the form column=value or column__op=value. For example, to return just repositories with the Apache 2 license and more than 10 stars:

{
  repos(filters: ["license=apache-2.0", "stargazers_count__gt=10"]) {
    nodes {
      full_name
      stargazers_count
      license {
        key
      }
    }
  }
}

This is the same format used for querystring arguments to the Datasette table view, see column filter arguments in the Datasette documentation.

Pagination

By default the first 10 rows will be returned. You can control this using the first: argument.

{
  repos(first: 20) {
    totalCount
    pageInfo {
      hasNextPage
      endCursor
    }
    nodes {
      full_name
      stargazers_count
      license {
        key
      }
    }
  }
}

The totalCount field returns the total number of records that match the query.

Requesting the pageInfo.endCursor field provides you with the value you need to request the next page. You can pass this to the after: argument to request the next page.

{
  repos(first: 20, after: "134874019") {
    totalCount
    pageInfo {
      hasNextPage
      endCursor
    }
    nodes {
      full_name
      stargazers_count
      license {
        key
      }
    }
  }
}

The hasNextPage field tells you if there are any more records.

Auto camelCase

The names of your columns and tables default to being matched by their representations in GraphQL.

If you have tables with names_like_this you may want to work with them in GraphQL using namesLikeThis, for consistency with GraphQL and JavaScript conventions.

You can turn on automatic camelCase using the "auto_camelcase" plugin configuration setting in metadata.json, like this:

{
    "plugins": {
        "datasette-graphql": {
            "auto_camelcase": true
        }
    }
}

Still to come

See issues for a full list. Planned improvements include:

• Canned query support
• Ability to allowlist specific tables, views and canned queries

Development

To set up this plugin locally, first checkout the code. Then create a new virtual environment:

cd datasette-graphql
python3 -mvenv venv
source venv/bin/activate

Or if you are using pipenv:

pipenv shell

Now install the dependencies and tests:

pip install -e '.[test]'

To run the tests:

pytest