javascript - Sequelize - self 引用有很多关系

Question

我正在将 Sequelize 与 Mysql 一起使用。

我有一张 table :

Items

包含以下字段:

{Id,Name,Price}

我想在项目中与他自己建立一个 self 关系。能够执行 Item.subItems 并获取属于该项目的所有子项目的列表的目标。

请告诉我如何在

中包含新模型

include:[{model:SubItem}]... when i fetch the a query.

我尝试了很多关系选项:

Item.hasMany(Item,{ through: SubItem,as:'subItems'});

Item.hasMany(Item);

感谢您的帮助!

Answer 1

创建自引用

Item.hasMany(Item, {as: 'Subitems'}) 

使用包含查找子项

Item.find({where:{name: "Coffee"},include:[{model: Item, as: 'Subitems'}]})

请参阅下面的示例代码，

var Sequelize = require('sequelize')
, sequelize = new Sequelize("test", "root", "root", {logging: false})
, Item    = sequelize.define('Item', { name: Sequelize.STRING })

Item.hasMany(Item, {as: 'Subitems'})


var chainer = new Sequelize.Utils.QueryChainer
, item  = Item.build({ name: 'Coffee' })
, subitem1 = Item.build({ name: 'Flat White' })
, subitem2 = Item.build({ name: 'Latte' })


sequelize.sync({force:true}).on('success', function() {
  chainer
    .add(item.save())
    .add(subitem1.save())
    .add(subitem2.save())

  chainer.run().on('success', function() {
    item.setSubitems([subitem1, subitem2]).on('success', function() { 

    /*  One way 
      item.getSubitems().on('success', function(subitems) {
        console.log("subitems: " + subitems.map(function(subitem) { 
          return subitem.name 
        }))
      })
    */

    //The include way you asked
    Item.find({where:{name: "Coffee"},include:[{model: Item, as: 'Subitems'}]}).success(function(item) {
         console.log("item:" + JSON.stringify(item));
    })

  })
}).on('failure', function(err) {
    console.log(err)
  })
})

日志数据如下:

item:{"id":1,"name":"Coffee","createdAt":"2014-08-05T06:25:47.000Z","updatedAt":"2014-08-05T06:25: 47.000Z","ItemId":null,"subitems":[{"id":2,"name":"Flat White","createdAt":"2014-08-05T06:25:47.000Z","updatedAt ":"2014-08-05T06:25:47.000Z","ItemId":1},{"id":3,"name":"Latte","createdAt":"2014-08-05T06:25: 47.000Z","updatedAt":"2014-08-05T06:25:47.000Z","ItemId":1}]}