Express中的graphql错误，节点js

我正在尝试在express中运行graphql server。但它会抛出以下错误。

var graphqlHTTP = require('express-graphql'); // express graphql
var { buildSchema } = require('graphql');  // graphql
var schema=buildSchema(
    type Query {
        name:String});

var classifyRoot={
     name:()=>{
        classified.find({name:"shoes"},function(err,classified){
            //res.render("card",{classifieds:classifieds});
            return classified.name;
        });
    },};
app.use('/graphql', graphqlHTTP({
  schema: schema,
  rootValue: classifyRoot,
  graphiql: true,
}));

buildSchema的论据应该是字符串。 （注意back-ticks）

var schema=buildSchema(`
    type Query {
        name:String
    }
`);