前面几篇文章都是说的查询(Query)操作,这一篇讲一下变更操作。还是老样子,看一个简单的例子。
mkdir myapp
cd myapp
npm init (一路回车)
npm install @apollo/server graphql
创建 schema.graphql 文件,内容如下:
type User {
id: ID!
name: String!
email: String!
}
type Query {
users: [User],
}
type Mutation {
createUser(name: String!, email: String!) : User!
}
schema {
query: Query
mutation: Mutation
}
schema 文件主要包括:
创建 resolvers.js 文件,内容如下:
const user1 = {id: 1, name: 'user1', email: 'user1@gmail.com'};
const user2 = {id: 2, name: 'user2', email: 'user2@gmail.com'};
const user3 = {id: 3, name: 'user3', email: 'user3@gmail.com'};
const users = [user1, user2, user3];
const resolvers = {
Query: {
users: () => users,
},
Mutation: {
createUser(obj, args, context, info) {
let user = {id: users.length + 1,name: args.name, email: args.email};
users.push(user);
return user;
}
}
};
module.exports = resolvers;
处理器文件主要包括
创建 server.js 文件,内容如下:
const { ApolloServer } = require('@apollo/server');
const { startStandaloneServer } = require('@apollo/server/standalone');
const fs = require("fs");
const typeDefs = fs.readFileSync('./schema.graphql').toString();
const resolvers = require('./resolvers');
const server = new ApolloServer({
typeDefs,
resolvers,
});
startStandaloneServer(server).then(function(data) {
console.log(`🚀 Server ready at ${data.url}`);
});
node server.js
服务启动后,访问 http://localhost:4000 进行测试。
变更请求
mutation createUser($name: String!, $email: String!) {
createUser(name: $name, email: $email) {
id,
name,
email
}
}
变更请求参数
{
"name": "newuser",
"email": "newuser@gmail.com"
}
变更返回结果,返回新创建的 User 对象
{
"data": {
"createUser": {
"id": "4",
"name": "newuser",
"email": "newuser@gmail.com"
}
}
}