获取当前表中不存在的Id分组的数量总和

Question

我有三个模型，看起来像这样：

const Reagent = sequelize.define('reagent', {
    name: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    ...
  })
  const Box = sequelize.define('box', {
    code: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
    },
    quantity: {
      type: DataTypes.INTEGER,
      allowNull: false,
    },
    ...
  })

  const BoxActivity = sequelize.define('boxActivity', {
    quantity: {
      type: DataTypes.INTEGER,
      allowNull: false,
    },
    date: {
      type: DataTypes.Date,
      allowNull: false,
    }
  })
Reagent.hasMany(Box);
Box.belongsTo(Reagent);
BoxActivity.belongsTo(Box);
Box.hasMany(BoxActivity);

我想获取带有数量总和的试剂列表（来自BoxActivity的

quantity

）模型，但我不知道如何实现这一点。 我写过这个：

await BoxActivity.findAll({
      attributes: ['boxId', [sequelize.fn('SUM', sequelize.col('quantity')), 'totalQuantity']],
      group: ['boxId'], // I need it grouped by reagent not box.
      where: {
        quantity: {
          [Op.gt]: 0
        }
      }
    })

接下来我可以尝试什么？

Answer 1

您需要在架构中定义外键引用，然后在查询中您可以像这样包含它们

modelA.findAll({
    include:[
        {model:modelB,attributes:[]},
        {model:modelC,attributes:[]}
    ],
    attributes:[
        //here you can access and manipulate modelB and modelC's columns 
        // like this sequelize.col('"modelB"."id"') and even use them in 
        //group by or order by
    ]

})