npm install koa-session-sequelize

var session = require('koa-session-store'); // or you can use 'koa-generic-session'
var Sequelize = require('sequelize');


var koa = require('koa');

// instantiation Sequelize see [Sequelize API Reference](https://github.com/sequelize/sequelize/wiki/API-Reference) for more detail
var sequelize = new Sequelize('test', 'username', '***', {  // instantiation
  dialect: 'sqlite',
  storage: ':memory:'
});

var sequelizeStore = require('koa-session-sequelize');

var app = koa();

app.keys = ['some secret key'];  // needed for cookie-signing

app.use(session({
  store: sequelizeStore.create(sequelize, {
    table: 'sessions',   // (optional) table to store sessions (default to 'sessions')
    model: 'Session',    // (optional) model to represent session (default to 'Session')
    dataField: { type: Sequelize.STRING, allowNull: true }  // (optinal) dataField definition (defaults to: { type: Sequelize.STRING, allowNull: true })
                                                            // type of this field should be those that can hold string data
  })
}));

app.use(function *() {
  var n = this.session.views || 0;
  this.session.views = ++n;
  this.body = n + ' views';
});

app.listen(3000, function () {
  console.log('listening on port 3000');
});

npm install && npm test