apollosolutions/example-subgraph-mongodb

MongoDB Atlas Demo

This repository demonstrates how to connect to MongoDB Atlas from a subgraph and make the data available via the Router. It demonstrates how you could in theory expose a MongoDB-like filter that is passed directly to MongoDB for filtering down returned data as well as a more demand-driven approach of using specific graphql arguments.

Running the Example

1. Make a copy of subgraph/.env.sample to subgraph/.env and update the MONGO_CONNECTION_STRING with your connection string.
2. Run the subgraph from the /subgraph directory with npm run dev
3. In the /router directory, download the router by running ./download_router.sh
4. In the /router directory, compose the schema by running ./create_local_schema.sh
5. In the /router directory, run the router by running ./start_router.sh

You can now open the Router at http://127.0.0.1:4000/ and start querying.

Example Queries

Basic

query Basic {
  patients {
    firstName
    lastName
    patientId
  }
}

With Arguments

query WithWhere ($where: JSONObject) {
  patients(where: $where) {
    firstName
    lastName
    patientId
  }
}

Variables:

{
  "where": { "patientId": { "_eq": 1 } }
}

Complex Filter

query WhereMore($where: JSONObject) {
  patients(where: $where) {
    firstName
    lastName
  }
}

Variables:

{
  "where": {
    "_and": [
      { "sex": { "_eq": "Female" }},
      { "healthState.diabetes": { "_eq": true }}
    ]
  }
}

Single Patient (Demand Driven Design)

query Patient($patientId: ID!) {
  patient(patientId: $patientId) {
    firstName
    lastName
    patientId
  }
}

Variables:

{
  "patientId": 1
}