Node Js迁移问题(未处理的拒绝SequelizeDatabaseError指定的键太长)

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

const User = sequelize.define('User', {
  username: {
    type: DataTypes.STRING(191), // 修改长度为191
    allowNull: false,
    unique: true
  }
});

module.exports = {
  up: async (queryInterface, Sequelize) => {
    await queryInterface.createTable('Users', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER
      },
      username: {
        type: Sequelize.STRING(191),
        allowNull: false,
        unique: true,
        collate: 'utf8mb4_unicode_ci' // 指定排序规则
      }
    }, {
      charset: 'utf8mb4' // 指定字符集
    });
  },
  down: async (queryInterface, Sequelize) => {
    await queryInterface.dropTable('Users');
  }
};

CREATE TABLE Users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  username VARCHAR(191) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL UNIQUE,
  INDEX idx_username (username(191))
) DEFAULT CHARSET=utf8mb4;