Yii's updateByPk keeps returning 0 - yii

Question

I'm trying to update my user table, which my code does. but for some reason it keeps executing the else statement.
in the documentation it states that updateByPk should return the number of rows being updated. Which should be 1. what am i missing here? and how do i check if the table has been updated successfully?
if (User::model()->updateByPk($model->id, array("last_login"=> Shared::timeNow())))
{
Yii::app()->user->login($identity, $duration);
echo json_encode(array('error' => false, 'success' => url(app()->users->getHomeUrl())));
Yii::app()->end();
}
else {
echo json_encode(array('error' => 'Could not update user info', 'code' => 'auth'));
Yii::app()->end();
}
my table schema is this
CREATE TABLE IF NOT EXISTS `user` (
`id` int(10) unsigned NOT NULL,
`username` varchar(100) DEFAULT NULL,
`email` varchar(255) NOT NULL,
`first_name` varchar(45) NOT NULL,
`last_name` varchar(45) NOT NULL,
`gender` char(1) DEFAULT NULL,
`birthday` date DEFAULT '0000-00-00',
`address` varchar(255) DEFAULT NULL,
`city` varchar(45) DEFAULT NULL,
`state` varchar(45) DEFAULT NULL,
`website` text,
`postal_code` varchar(45) DEFAULT NULL,
`phone` varchar(45) DEFAULT NULL,
`password` varchar(63) DEFAULT NULL,
`activate` varchar(63) NOT NULL DEFAULT '1',
`create_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`last_login` datetime DEFAULT NULL,
`password_reset` int(11) unsigned DEFAULT NULL,
`admin` tinyint(1) unsigned NOT NULL DEFAULT '0',
`email_verified` tinyint(1) unsigned DEFAULT NULL,
`login_disabled` tinyint(1) unsigned NOT NULL DEFAULT '0',
`oauth_id` bigint(20) DEFAULT NULL,
`oauth_username` varchar(255) DEFAULT NULL,
`oauth_provider` varchar(10) DEFAULT NULL,
`oauth_email` varchar(255) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

Answer 1

You should check $model exits first otherwise updateByPk can return 0
if ($model && User::model()->updateByPk($model->id, array("last_login"=> Shared::timeNow())))

Answer 2

Your table does not specify a primary key. Yet you update by primary key.
You have a few choices.
Change your table structure to include a primary key
Use another update method. For example, Update() allow you to pass a criteria object.

Answer 3

Know it's old, but : https://www.php.net/manual/en/pdostatement.rowcount.php
If the last SQL statement executed by the associated PDOStatement was a SELECT statement, some databases may return the number of rows returned by that statement. However, this behaviour is not guaranteed for all databases and should not be relied on for portable applications.
And Yii1 use rowCount

Answer 4

Model can be not updated because last_login attribute has not valid value.
Try get model errors ($model->errors()) or check model by $model->validate();
Why you not implement this as follows:
$model->last_login = Shared::timeNow();
if ($model->save())
{
Yii::app()->user->login($identity, $duration);
echo json_encode(array('error' => false, 'success' => url(app()->users->getHomeUrl())));
Yii::app()->end();
}
else {
echo json_encode(array('error' => 'Could not update user info', 'code' => 'auth'));
Yii::app()->end();
}