合并包含联结表中的属性

Question

I'm building a shop, where in the database i have orders and items. Here's the code for the models:

Item:

var Sequelize = require('sequelize')
var sequelize = require('./sequelize')
var Item = sequelize.define('item', {
  image: {
    type: Sequelize.STRING,
    allowNull: false
  },
  itemName: {
    type: Sequelize.STRING,
    allowNull: false,
    field: 'item_name'
  },
  price: {
    type: Sequelize.INTEGER,
    allowNull: false
  }
})

module.exports = Item

Order:

var Sequelize = require('sequelize')
var sequelize = require('./sequelize')
var Order = sequelize.define('order', {
  orderNumber: {
    primaryKey: true,
    type: Sequelize.UUID,
    defaultValue: Sequelize.UUIDV4
  },
  shop: {
    type: Sequelize.INTEGER
  },
  location: {
    type: Sequelize.STRING
  }
})

module.exports = Order

They are related through belongs to many:

Item.belongsToMany(Order, {through: OrderItem})
Order.belongsToMany(Item, {through: OrderItem})

The OrderItem has an additional field, 'count', which i need to return:

var Sequelize = require('sequelize')
var sequelize = require('./sequelize')

var OrderItem = sequelize.define('OrderItem', {
  count: Sequelize.INTEGER
})

module.exports = OrderItem

However, when i try to include the OrderItem model, it doesn't work. No errors, nothing. The query just doesn't return:

Order.findAll({
      where: {
        userId: userId
      },
      include: [{
        model: Item,
        include: [OrderItem]
      }]
    }).then(orders => {
      console.log(orders)
      res.status(200).json(orders)
    })

How to get what i need from sequeilize?

Answer 1

You may try something like this:

  Order.findAll({
      where: {
        userId: userId
      },
      include: [{ model: Item, 
        as:'item', 
        through:{attributes:['count']} // this may not be needed
      }]
  }).then(orders => {
    console.log(orders)
    res.status(200).json(orders)
  })

Also, your models must have a right naming strategy. Eg :

Item - must have itemId field instead of itemNumber, Order - must have orderId as primary field

OrderItem's structure:

var OrderItem = sequelize.define('OrderItem', {
  orderId: Sequelize.INTEGER,
  itemId: Sequelize.INTEGER,
  count: Sequelize.INTEGER
})

Another one is to use direct names of related fields and models when you use belongsToMany()

More here: http://docs.sequelizejs.com/en/latest/docs/associations/

Answer 2

I know this is year later, but yet..

You can use the property joinTableAttributes to get a junction table fields .

for example :

Order.findAll({
  where: {
    userId: userId
  },
  joinTableAttributes: ['count'],
  include: [{
    model: Item,
  }]
}).then(orders => {
  console.log(orders)
  res.status(200).json(orders)
})

Answer 3

Turns out that the OrderItem is already nested inside the Item object. However, this doesn't make a nice return format , so the question is still open.