silverstripe-framework/docs/en/howto/track-member-logins.md

Howto: Track Member Logins

Sometimes its good to know how active your users are, and when they last visited the site (and logged on). A simple LastVisited property on the Member record with some hooks into the login process can achieve this. In addition, a NumVisit property will tell us how often the member has visited. Or more specifically, how often he has started a browser session, either through explicitly logging in or by invoking the "remember me" functionality.

:::php
<?php
class MyMemberExtension extends DataExtension {
	private static $db = array(
		'LastVisited' => 'Datetime',
		'NumVisit' => 'Int',
	);

	public function memberLoggedIn() {
		$this->logVisit();
	}

	public function memberAutoLoggedIn() {
		$this->logVisit();
	}

	public function updateCMSFields(FieldList $fields) {
		$fields->addFieldsToTab('Root.Main', array(
			ReadonlyField::create('LastVisited', 'Last visited'),
			ReadonlyField::create('NumVisits', 'Number of visits')
		));
	}

	protected function logVisit() {
		if(!Security::database_is_ready()) return;
		
		DB::query(sprintf(
			'UPDATE "Member" SET "LastVisited" = %s, "NumVisit" = "NumVisit" + 1 WHERE "ID" = %d',
			DB::getConn()->now(),
			$this->owner->ID
		));
	}
}

Now you just need to apply this extension through your config:

:::yml
Member:
	extensions:
		- MyMemberExtension