Sequelize:嵌套列的求和值

const { Model, DataTypes } = require('sequelize');
const sequelize = new Sequelize('<database>', '<username>', '<password>', {
  host: '<host>',
  dialect: '<dialect>'
});

class Order extends Model {}
Order.init({
  // 订单属性定义
}, { sequelize, modelName: 'order' });

class OrderItem extends Model {}
OrderItem.init({
  // 商品项属性定义
  amount: DataTypes.INTEGER // 数量属性
}, { sequelize, modelName: 'order_item' });

Order.hasMany(OrderItem); // 定义订单和商品项的关联

const result = await Order.findAll({
  attributes: [
    'id', // 其他订单属性
    [sequelize.fn('SUM', sequelize.literal('"order_items"."amount"')), 'totalAmount'] // 计算商品项数量的总和
  ],
  include: [{
    model: OrderItem,
    attributes: []
  }],
  group: ['order.id']
});