sequelize cli creating a polymorphic one to many and many to many relation

Question

I want to create a polymorphic relation like in the diagram using sequalize-cli es6 format.

I have created this model using sequelize-cli npx sequelize-cli model:generate --name Post --attributes name:string npx sequelize-cli model:generate --name Video --attributes title:string npx sequelize-cli model:generate --name Comment --attributes comments:text,comments_id:integer,comments_type:string

It generate following files Model files:

'use strict';
const {
  Model
} = require('sequelize');
module.exports = (sequelize, DataTypes) => {
  class Post extends Model {
    /**
     * Helper method for defining associations.
     * This method is not a part of Sequelize lifecycle.
     * The `models/index` file will call this method automatically.
     */
    static associate(models) {
      // define association here
    }
  }
  Post.init({
    name: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'Post',
  });
  return Post;
};

'use strict';
const {
  Model
} = require('sequelize');
module.exports = (sequelize, DataTypes) => {
  class Video extends Model {
    /**
     * Helper method for defining associations.
     * This method is not a part of Sequelize lifecycle.
     * The `models/index` file will call this method automatically.
     */
    static associate(models) {
      // define association here
    }
  }
  Video.init({
    title: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'Video',
  });
  return Video;
};

'use strict';
const {
  Model
} = require('sequelize');
module.exports = (sequelize, DataTypes) => {
  class Comment extends Model {
    /**
     * Helper method for defining associations.
     * This method is not a part of Sequelize lifecycle.
     * The `models/index` file will call this method automatically.
     */
    static associate(models) {
      // define association here
    }
  }
  Comment.init({
    comments: DataTypes.TEXT,
    comments_id: DataTypes.INTEGER,
    comments_type: DataTypes.STRING
  }, {
    sequelize,
    modelName: 'Comment',
  });
  return Comment;
};

Migration files:

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('Posts', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      name: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('Posts');
  }
};

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('Videos', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      title: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('Videos');
  }
};

'use strict';
/** @type {import('sequelize-cli').Migration} */
module.exports = {
  async up(queryInterface, Sequelize) {
    await queryInterface.createTable('Comments', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      comments: {
        type: Sequelize.TEXT
      },
      comments_id: {
        type: Sequelize.INTEGER
      },
      comments_type: {
        type: Sequelize.STRING
      },
      createdAt: {
        allowNull: false,
        type: Sequelize.DATE
      },
      updatedAt: {
        allowNull: false,
        type: Sequelize.DATE
      }
    });
  },
  async down(queryInterface, Sequelize) {
    await queryInterface.dropTable('Comments');
  }
};

Can anyone explain to me how to modify this files to make relationship like in the diagram. I am new to sequalize-cli orm .. Thank you.

I am trying to build a website. Using sequalize orm I will make my work much easier..

Answer 1

I think the below documentation will help U URL: https://sequelize.org/docs/v6/advanced-association-concepts/eager-loading/

Answer:
Posts.hasMany(Comments)
Comments.belongsTo(Posts)

Videos.hasMany(Comments)
Comments.belongsTo(Videos)