PrimaryKey auto-increment concept is not working in persistencejs

[bairaginath]

var persistence = require('persistencejs');
var persistenceStore = persistence.StoreConfig.init(persistence, { adaptor: 'mysql' });
persistenceStore.config(persistence, 'localhost', 3306, 'nodedb', 'root', 'root');

var session = persistenceStore.getSession();

var User = persistence.define('user', {
email: "TEXT",
password : "TEXT",
first_name : "TEXT",
last_name : "TEXT"
});

var user = new User({email:'[email protected]',password : 'world',first_name : "world",last_name:'world'});

session.add(user);
session.transaction(function(tx) {
session.flush(tx,function(result){

    console.log(result.insertId);
});

});

session.close();

it alway create random primary key and also some time duplicate key problem occurs.
below the following sql create query :

CREATE TABLE user (
id int(11) NOT NULL AUTO_INCREMENT,
email varchar(45) NOT NULL,
password varchar(45) NOT NULL,
first_name varchar(45) DEFAULT NULL,
last_name varchar(45) DEFAULT NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=latin1;