Graphql的使用

const express = require('express')
//构建轮廓的方法
const { buildSchema } = require('graphql')
//连接器
const { graphqlHTTP } = require('express-graphql')

//构建轮廓
const Schema = buildSchema(`
type Query{
    hello:String
}`)

const root = {
    hello: () => {

        return "hello gtaphql"
    },
}

const app = express()

app.use('/graphql', graphqlHTTP(
    {
        schema: Schema,
        rootValue: root,
        //开启调试器
        graphiql: true
    }
))

app.listen(3000)

//query只能查询，要用mutation来进行增删改
var Schema = buildSchema(`
    type Account{
        name:String,
        age:Int,
        address:String
    }
    type Film{
        id:Int,
        name:String,
        grade:Float,
        price:Int
    }
    input FilmInput{
        
        name:String,
        grade:Float,
        price:Int
    }
    type Query{
        hello:String,
        getAllNames:[String],
        getAccount:Account,
        getFilms:[Film],
        getFilmDetail(id:Int!):Film
    }
    type Mutation {
        createFilm(input:FilmInput):Film,
        updateFilm(id:Int!,input:FilmInput):Film,
        deleteFilm(id:Int!):String
    }
`)

//对应数据
var data = [
    {
        id: 1,
        name: 'kongfu',
        grade: 9,
        price: 39

    },
    {
        id: 2,
        name: '大话西游',
        grade: 9.7,
        price: 27

    }, {
        id: 3,
        name: '喜羊羊与灰太狼',
        grade: 9,
        price: 48

    }
]
var root = {
    hello: () => { return 'hello world' },
    getAllNames: () => {
        return ['赵', '钱', '孙', '李']
    },
    getAccount: () => {
        return {
            name: 'wang',
            age: 3,
            address: 'cq'
        }
    },
    getFilms: () => {
        return data

    },
    getFilmDetail({ id }) {
        return data.filter((item) => item.id === id)[0]
    },
    createFilm({ input }) {
        var obj = { id: data.length + 1, ...input }
        data.push(obj)
        return obj
    },
    updateFilm({ id, input }) {
        console.log(id, input)
        data.map(item => {
            if (item.id === id) {
                console.log('map', item.id)
                item.name = input.name
                item.grade = input.grade
                item.price = input.price
            }

        })
        var obj = data.filter(item => item.id === id)[0]
        return obj
    },
    deleteFilm({ id }) {
        console.log(data)
        let flag = true
        const newdata = data.filter(item => {
            if (item.id === id) {
                flag = false
                return
            }
            return item
        })
        data = [...newdata]
        return flag ? '未找到该数据' : '删除成功'
    }
}