outline/server/migrations/20160911232911-user-unique-fields.js

module.exports = {
  up: function (queryInterface, Sequelize) {
    queryInterface.changeColumn(
      'users',
      'email',
      {
        type: Sequelize.STRING,
        unique: true,
        allowNull: false,
      }
    );
    queryInterface.changeColumn(
      'users',
      'username',
      {
        type: Sequelize.STRING,
        unique: true,
        allowNull: false,
      }
    );
  },

  down: function (queryInterface, Sequelize) {
    queryInterface.changeColumn(
      'users',
      'email',
      {
        type: Sequelize.STRING,
        unique: false,
        allowNull: true,
      }
    );

    queryInterface.changeColumn(
      'users',
      'username',
      {
        type: Sequelize.STRING,
        unique: false,
        allowNull: true,
      }
    );
  },
};