text: 'use strict';
  
  module.exports = {
    up: async (queryInterface, Sequelize) => {
      queryInterface.addConstraint('requests', {
        type: 'unique',
        fields: ['classroom_id', 'user_id'],
        name: 'requests_unique_index'
      })
    },
  
    down: async (queryInterface, Sequelize) => {
      queryInterface.removeConstraint('requests', 'requests_unique_index')
    }
  };
  