依赖

1. express
2. express-graphql
3. graphql

创建服务器

先要用express搭建服务器

const express = require('express')
const http = require('http')
const R = require('ramda')

const PORT = process.env.PORT ? process.env.PORT : 22333

let app = express()
app.get('/', (req, res) => {
  res.send('hello')
})
const httpServer = http.createServer(app)
httpServer.listen(PORT, () => {
  console.log(`http://localhost:${PORT}/`)
})

要注意这里不要使用express的listen，方便以后对接https。

Schema

新建schema.js的文件：

  const { buildSchema } = require('graphql')

  module.exports = buildSchema(`
    type Query{
      hello:String
    }
  `)

Resolver

新建resolver.js

module.exports = {
  hello: ()=>'hello'
}

在express中加入graphql中间件

const express = require('express')
const http = require('http')
const R = require('ramda')

const gqResolver = require('./graphql/resolver')
const gqSchema = require('./graphql/schema')

const PORT = process.env.PORT?process.env.PORT:22333

let app = express()

app.use('/graphql', expressGraphQL({
  schema: gqlSchema,
  rootValue: resolver,
  graphiql: true
}))
app.get('/', (req, res) => {
  res.send('hello')
})

const httpServer = http.createServer(app)
httpServer.listen(PORT, () => {
  console.log(`http://localhost:${PORT}/`)
})

如果一切顺利的话启动服务器之后打开localhost:PORT/graphql , 听过会出现如下的画面，这时打开右上角的docs，就可以查询之前创建的API了。

graphql.png

测试

接下来在左边的命令窗口中输入

{hello}

然后点击播放按钮就可以看到服务器返回的结果了

graphql2.png