How to execute GraphQL query from server

问题

I am using graphql-express to create an endpoint where I can execute graphql queries in. Although I am using Sequelize with a SQL database it feels wrong to use it directly from the server outside of my graphql resolve functions. How do I go about querying my graphql API from the same server as it was defined in?

This is how I set up my graphql endpoint:

const express = require('express');
const router = express.Router();
const graphqlHTTP = require('express-graphql');
const gqlOptions = {
   schema: require('./schema')
};
router.use('/', graphqlHTTP(gqlOptions));

modules.exports = router;

Basically what I want is to be able to do something like this:

query(`
  {
    user(id: ${id}) {
      name
    }
  }
`)

How would I create this query function?

回答1:

GraphQL.js itself does not require a http server to run. express-graphql is just a helper to mount the query resolver to a http endpoint.

You can pass your schema and the query to graphql, it'll return a Promise that'll resolve the query to the data.

graphql(schema, query).then(result => {
  console.log(result);
});

So:

const {graphql} = require('graphql');
const schema = require('./schema');
function query (str) {
  return graphql(schema, str);
}

query(`
  {
    user(id: ${id}) {
      name
    }
  }
`).then(data => {
  console.log(data);
})

回答2:

I would like to complete the answer from @aᴍɪʀ by providing the pattern for properly doing a query / mutation with parameters:

const params = {
  username: 'john',
  password: 'hello, world!',
  userData: {
    ...
  }
}

query(`mutation createUser(
          $username: String!,
          $password: String!,
          $userData: UserInput) {
  createUserWithPassword(
    username: $username,
    password: $password,
    userData: $userData) {
    id
    name {
      familyName
      givenName
    }
  }
}`, params)

This way, you don't have to deal with the string construction bits " or ' here and there.

来源：https://stackoverflow.com/questions/41424728/how-to-execute-graphql-query-from-server