P2M training exam

model.js

let userId = 10;
let User = {
  create: function (user) {
    return new Promise((resolve) => {
      setTimeout(() => {
        let r = {
          id: userId++,
          name: user.name
        }
        console.log(JSON.stringify(r));
        return resolve(r);
      }, 1000);
    });
  }
}
let projectId = 20;
let Project = {
  create: function (project) {
    return new Promise((resolve) => {
      setTimeout(() => {
        let r = {
          id: projectId++,
          name: project.name,
          onwerId: project.ownerId,
        }
        console.log(JSON.stringify(r));
        return resolve(r);
      }, 1000);
    });
  }
}
let taskId = 30;
let Task = {
  create: function (task) {
    return new Promise((resolve) => {
      setTimeout(() => {
        let r = {
          id: taskId++,
          title: task.title,
          projectId: task.projectId,
          assignTo: task.assignTo
        }
        console.log(JSON.stringify(r));
        return resolve(r);
      }, 1000);
    });
  }
}

Promise.md

使用Node.JS （版本>= 8)完成下题：

假设系统提供了三个函数：

• Project.create({name: 'P1', ownerId: 1}) 函数
  在数据库中的Project表中创建一条记录。函数返回一个Promise对象。resolve方法的参数是一个Project对象：{id: 1, name: 'P1', ownerId: 1}。
• Task.create({projectId: 1, title: 'T1', assignTo: 1})函数
  在数据库中的Task表中创建一条子记录。这个记录通过projectId和Project表关联。函数返回Promise对象，resolve对象例如：{id: 1, projectId: 1, title: 'T1', assignTo: 1}
• User.create({name: 'U1'})函数
  在数据库中的User表中创建一条记录。{id: 1, name: 'U1'}

model.js是上面三个函数的实现，请通过调用其中的方法完成下面的练习。

实现一段Javascript代码，创建如下的数据库记录。

  U1 -> User {name: 'U1'}
  U2 -> User {name: 'U2'}
  P1 -> Project {name: 'P1', ownerId: U1.id}
  T11 -> Task {projectId: P1.id, assignTo: U1.id, title: 'T11'}
  T12 -> Task {projectId: P1.id, assignTo: U2.id, title: 'T12'}
  P2 -> Project {name: 'P2', ownerId: U2.id}
  T21 -> Task {projectId: P2.id, assignTo: U1.id, title: 'T21'}
  T22 -> Task {projectId: P2.id, assignTo: U2.id, title: 'T22'}

其中 projectId: P1.id表示，创建时需要将之前创建的P1对象的id属性作为新对象的属性的值。

程序运行输出应该类似下面内容：（注：顺序不做要求)

{"id":10,"name":"U1"}
{"id":11,"name":"U2"}
{"id":20,"name":"P1","onwerId":10}
{"id":21,"name":"P2","onwerId":11}
{"id":30,"title":"T11","projectId":20,"assignTo":10}
{"id":31,"title":"T12","projectId":20,"assignTo":11}
{"id":32,"title":"T21","projectId":21,"assignTo":10}
{"id":33,"title":"T22","projectId":21,"assignTo":11}