GraphQL Subscription using Hasura C# example

• .Net core 5
• GraphQL.Client 3.2.4
• GraphQL.Client.Serializer.Newtonsoft 3.2.4

Documentation

https://hasura.io/docs/latest/graphql/core/databases/postgres/subscriptions/index.html

subscription

See below the subscription as an example based on 2 tables vehicle and vehicle_location to get the lasted vehicle location

subscription getLocation($vehicleId: Int!) {
  vehicle_location(where: {vehicle_id: {_eq: $vehicleId}}, order_by: {timestamp: desc}, limit: 1) {
    id
    location
    timestamp
    vehicle {
      id
      vehicle_number
    }
  }
}

How do run

1. Run Hasura using the docker compose file

docker-compose up -d

2. Create the tables vehicle and vehicle_location

3. Run the C# console app

4. Add some data using the Hasura UI, should see the app is displaying the latest location.