Yes, I know that this is a borderline absurd web stack for the ubiquitous TODO application but I had a lot of trouble getting this all to work. I started using these things for a more ambitious project and I'd love to spare you the trouble. So here's some basic boilerplate to get you up and running.

Here's what does what:

Before you get started, make sure that you have PostgreSQL, Rust, Cargo, and the Diesel CLI installed and that you have Postgres running somewhere.

# Fetch the repo
git clone https://github.com/lucperkins/rust-actix-diesel-postgres-juniper
cd rust-actix-diesel-postgres-juniper

# Set up the database
cp .env.example .env # Modify this file to match your Postgres installation

diesel setup
diesel migration run

cargo run # could take a while!

The DATABASE_URL can be any Postgres installation. For my purposes, I have it set to postgres://localhost:5432/todos.

Once the server is running, you can access the GraphQL Playground UI at http://localhost:4000/graphql.

The server implements the following GraphQL schema:

type Todo {
  id: ID!
  task: String!
  done: Boolean!
}

input CreateTodoInput {
  task: String!
  done: Boolean
}

type Query {
  allTodos: [Todo!]!
  getTodoById(id: Int): Todo
}

type Mutation {
  createTodo(input: CreateTodoInput): Todo
  markTodoAsDone(id: Int): Todo
  markTodoAsNotDone(id: Int): Todo
}

schema {
  Query
  Mutation
}

Get it? Anyway, here's some areas for improvement (pull requests very much welcome):

• Error handling — Right now errors basically propagate directly from Diesel/Postgres into the GraphQL JSON output, which is subpar. If any of you can point me to good educational resources on this, please file an issue!
• Better execution engine — The server uses the extremely powerful actix-web but the actual DB interactions don't use Actix actors and it'd take this setup to the next level if they did.
• Use macros for schema generation — The powerful juniper_from_schema macro could help reduce boilerplate and improve development velocity.

I'm basically a beginner with Rust and would not have been able to put this together without peeking long and hard at the example projects and blog posts listed below. The lower-level bits you see here are basically stolen from BrendanBall. All that I've added is the Todos data construct for executing queries.

• BrendanBall/example-actix-web-juniper-diesel
• iwilsonq/rust-graphql-example
• dancespiele/listing_people_api_actix

• Building Powerful GraphQL Servers with Rust
• [Rust] juniper + diesel + actix-webでGraphQLしてみる