Group By with Sequelize

const { Sequelize, DataTypes } = require('sequelize');

const sequelize = new Sequelize('database', 'username', 'password', {
  host: 'localhost',
  dialect: 'mysql'
});

const User = sequelize.define('User', {
  id: {
    type: DataTypes.INTEGER,
    primaryKey: true,
    autoIncrement: true
  },
  name: {
    type: DataTypes.STRING
  },
  age: {
    type: DataTypes.INTEGER
  }
}, {
  tableName: 'Users',
  timestamps: false
});

module.exports = User;

const User = require('./models/User');

User.findAll({
  attributes: [
    'age',
    [sequelize.fn('COUNT', sequelize.col('age')), 'userCount']
  ],
  group: 'age'
})
  .then(result => {
    result.forEach(row => {
      console.log(`Age ${row.age}: ${row.userCount} users`);
    });
  })
  .catch(error => {
    console.error('Error:', error);
  });