Question

我正在使用sequelize.js V.5创建一个简单的api，用于发布书评。注释应该通过书号属于该书，并且与发布用户相同。

我不太确定如何创建它。

firebase.auth().onAuthStateChanged(user => {
  console.log('user', user) 
});

Answer 1

根据文档，您需要关联对象

直接来自文档的标准示例

关联对象

Because Sequelize is doing a lot of magic, you have to call Sequelize.sync after setting the associations! Doing so will allow you the following:

Project.belongsToMany(Task)
Task.belongsToMany(Project)

Project.create()...
Task.create()...
Task.create()...

// save them... and then:
project.setTasks([task1, task2]).then(function() {
  // saved!
})

// ok, now they are saved... how do I get them later on?
project.getTasks().then(function(associatedTasks) {
  // associatedTasks is an array of tasks
})

// You can also pass filters to the getter method.
// They are equal to the options you can pass to a usual finder method.
project.getTasks({ where: 'id > 10' }).then(function(tasks) {
  // tasks with an id greater than 10 :)
})

// You can also only retrieve certain fields of a associated object.
project.getTasks({attributes: ['title']}).then(function(tasks) {
    // retrieve tasks with the attributes "title" and "id"
})

要删除创建的关联，您只需调用set方法即可，而无需指定特定ID：

// remove the association with task1
project.setTasks([task2]).then(function(associatedTasks) {
  // you will get task2 only
})

// remove 'em all
project.setTasks([]).then(function(associatedTasks) {
  // you will get an empty array
})

// or remove 'em more directly
project.removeTask(task1).then(function() {
  // it's gone
})

// and add 'em again
project.addTask(task1).then(function() {
  // it's back again
})

关于您的问题：

必须有类似的内容：

Comment.create(
    {
        // create new comment as you like
     }

然后是类似的（根据需要）

comment.setUser(user).then(function() {
  // saved!
})

comment.setBook(book).then(function() {
  // saved!
})

创建一个对象，该对象属于另外两个对象

1 个答案: