graphql查詢

首先下載express，express-graphql和graphql

var express = require('express');
var graphqlHTTP = require('express-graphql');
var { buildSchema } = require('graphql');

var schema = buildSchema(`
    type Account{
        name:String
        
    }

  type Query {
    hello: String
    account:Account,
    getClass(classNo:Int!):[String]
  },

`);
var root = { hello: () => 'Hello world!' ,
            account:()=>{return {name:'xx'}},
            getClass:({classNo})=>{
                const obj={1:['xx','yy']}
                return obj[classNo]
            }
};

var app = express();
app.use('/graphql', graphqlHTTP({
  schema: schema,
  rootValue: root,
  graphiql: true,
}));
app.listen(4000, () => console.log('Now browse to localhost:4000/graphql'));

客戶端請求數據

  <button class="btn">點擊</button>
    <script>
        var btn=document.getElementsByClassName('btn')[0];
        var Account=`query GetClass($classNo:Int!){getClass(classNo:$classNo)}`
        var variables={classNo:1}
        btn.onclick=function(){
            fetch('/graphql',{method:'post',headers:{'Content-Type':'application/json',
'Accept':'application/json'},body:JSON.stringify({query:Account,variables})}).then(data=>data.json()).then(data=>{console.log(data)})
        }
    </script>

 <button class="btn">點擊</button>
    <script>
        var btn=document.getElementsByClassName('btn')[0];
        btn.onclick=function(){
           
            var Account=`query {account{name},hello}`
            fetch('/graphql',{method:'post',headers:{'Content-Type':'application/json',
            'Accept':'application/json'},body:JSON.stringify({query:Account})}).then(data=>data.json())
            .then(data=>{console.log(data)})
        }
    </script>