why do i get this error in creating row in sequelize in node.js?

I have everything installed on my computer, but still I got these errors: Unhandled rejection SequelizeDatabaseError: SQLITE_ERROR: table Users has no column named last_name at Query.formatError (/Users/kamran/developer/WEB/WebCourse/p3/node_modules/sequelize/lib/dialects/sqlite/query.js:242:14) at /Users/kamran/developer/WEB/WebCourse/p3/node_modules/sequelize/lib/dialects/sqlite/query.js:47:29 at Statement.errBack (/Users/kamran/developer/WEB/WebCourse/p3/node_modules/sqlite3/lib/sqlite3.js:16:21)

here is my code:

'use strict';
module.exports = function(sequelize, DataTypes) {
  var User = sequelize.define('User', {
    first_name: DataTypes.STRING,
    last_name: DataTypes.STRING,
    username: DataTypes.STRING,
    password: DataTypes.STRING,
    photo_base64: DataTypes.STRING
  }, {
    classMethods: {
      associate: function(models) {
        // associations can be defined here
      }
    }
  });
  return User;
};

an here is my model:

var user = models.User.build({
            first_name:first_name,
            last_name:last_name,
            username:username,
            password:password,
            photo_base64:photo_base64
        });
        user.save().then(function(user) {
            console.log(user.get('username'));
        });