與 MYSQL 續集的一對多關系

Question

我有兩張桌子：

const attr = {
  name: {
    type: DataTypes.STRING,
  },
};
const Tags = createModel('Tags', attr, {});

和：

const attr = {
  tagId: {
    type: DataTypes.INTEGER,
    references: { model: 'Tags', key: 'id' },
  }
}

const Client = createModel('Client', attr, {})
Client.belongsTo(Tag, { foreignKey: 'tagId', as: 'tags' });

我的查詢是這樣的：

const clientCount = await Client.findAll({
      include: [ { model: Tags, as: 'tags' } ],
      attributes: { exclude: 'tagId' }
    });

這是我的回應：

{
      "id": 1,
      "createdAt": "2020-01-20T00:00:00.000Z",
      "updatedAt": "2020-01-22T00:00:00.000Z",
      "tags": {
          "id": 1,
          "name": "New tag",
          "createdAt": "2020-01-20T00:00:00.000Z",
          "updatedAt": "2020-01-20T00:00:00.000Z"
        }
}

但我希望我的標簽是一個數組，所以我來賓我必須定義一個一對多的關聯，但到目前為止我嘗試的一切都失敗了。

我想要的是標簽是一個數組，我可以在其中添加多個標簽對象：{

    "id": 1,
      "createdAt": "2020-01-20T00:00:00.000Z",
      "updatedAt": "2020-01-22T00:00:00.000Z",
      "tags": [
        {
          "id": 1,
          "name": "New tag",
          "createdAt": "2020-01-20T00:00:00.000Z",
          "updatedAt": "2020-01-20T00:00:00.000Z"
        }
  ]
}

Answer 1

方法1
我們需要新的 model 作為Client_Tag

const attr = {
    clientId: {
        type: DataTypes.INTEGER,
    },
    tagId: {
        type: DataTypes.INTEGER,
    },
};
const Client_Tag = createModel('Client_Tag', attr, {});

Client.belongsToMany(Tag, {
    foreignKey: 'clientId',
    otherKey: 'tagId',
    through: models.Client_Tag,
    as: 'tags'
});

const clientCount = await Client.findAll({
      include: [ { model: Tags, as: 'tags' } ],
      attributes: { exclude: 'tagId' }
});

方法2

const attr = {
    name: {
        type: DataTypes.STRING,
    },
    clientId: { // need clientId in tag model, and remove 'tagId' from client model
        type: DataTypes.INTEGER,
    }
};
const Tags = createModel('Tags', attr, {});

Client.belongsToMany(Tag, { foreignKey: 'tagId', as: 'tags' });