在 GraphQL 模式中创建类型时是否可以重命名字段？

Question

When defining the userType in the following GraphQL schema on the server, how can I rename the "name" field to "firstname" while still referring to the "name" field in fakeDatabase ?

The following code snippet has been copied from the official GraphQL docs

var express = require('express');
var graphqlHTTP = require('express-graphql');
var graphql = require('graphql');

// Maps id to User object
var fakeDatabase = {
  'a': {
    id: 'a',
    name: 'alice',
  },
  'b': {
    id: 'b',
    name: 'bob',
  },
};

// Define the User type
var userType = new graphql.GraphQLObjectType({
  name: 'User',
  fields: {
    id: { type: graphql.GraphQLString },
    // How can I change the name of this field to "firstname" while still referencing "name" in our database?
    name: { type: graphql.GraphQLString },
  }
});

// Define the Query type
var queryType = new graphql.GraphQLObjectType({
  name: 'Query',
  fields: {
    user: {
      type: userType,
      // `args` describes the arguments that the `user` query accepts
      args: {
        id: { type: graphql.GraphQLString }
      },
      resolve: function (_, {id}) {
        return fakeDatabase[id];
      }
    }
  }
});

var schema = new graphql.GraphQLSchema({query: queryType});

var app = express();
app.use('/graphql', graphqlHTTP({
  schema: schema,
  graphiql: true,
}));
app.listen(4000);
console.log('Running a GraphQL API server at localhost:4000/graphql');

Answer 1

Resolvers can be used for any type, not just Query and Mutation . That means you can easily do something like this:

const userType = new graphql.GraphQLObjectType({
  name: 'User',
  fields: {
    id: {
      type: graphql.GraphQLString,
    },
    firstName: {
      type: graphql.GraphQLString,
      resolve: (user, args, ctx) => user.name
    },
  }
})

The resolver function specifies, given the parent value, arguments for that field and the context, what a field for any instance of a type will resolve to. It could even always return the same static value each time.

Answer 2

There's also a library graphql-tools that let you transform your schema, we use that on our schema stitching service.

const { RenameTypes, transformSchema } = require("graphql-tools");

/*
 * Schema transformations:
 * Types:
 *  <> Task -> GetTask
 */

const transformMySchema = schema => {
  return transformSchema(schema, [
    new RenameTypes(function(name) {
      return name == "Task" ? "GetTask" : name;
    }),
  ]);
};

Read more : https://github.com/apollographql/graphql-tools/blob/513108b1a6928730e347191527cba07d68aadb74/docs/source/schema-transforms.md#modifying-types

Does this answer the question ?

Answer 3

Exactly what Daniel said. It does not matter what your resolver name is, you will resolve your user.name from your DB.