与 MYSQL 续集的一对多关系

Question

I have two tables:

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

and:

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

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

and my query is this:

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

and this is my response:

{
      "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"
        }
}

but I want my tags to be an array, so I guest I have to define a one to many association, but everything I tried so far failed.

What I want is tags to be an array, where I can add multiple tag objects: {

    "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

Method1
We need new model as 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' }
});

Method2

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' });