PDOHandler to log records to a database https://github.com/Seldaek/monolog/blob/master/doc/extending.md

PDOHandler.php

<?php

use Monolog\Logger;
use Monolog\Handler\AbstractProcessingHandler;

class PDOHandler extends AbstractProcessingHandler
{
	private $initialized = false;
	private $pdo;
	private $statement;

	public function __construct(PDO $pdo, $level = Logger::DEBUG, $bubble = true)
	{
		$this->pdo = $pdo;

		parent::__construct($level, $bubble);
	}

	protected function write(array $record)
	{
		if (!$this->initialized)
		{
			$this->initialize();
		}

		$this->statement->execute(array(
			'time' => $record['datetime']->format('Y-m-d H:i:s'),
			'channel' => $record['channel'],
			'level' => $record['level'],
			'level_name' => $record['level_name'],
			'message' => $record['message'],
			'context' => json_encode($record['context']),
			'extra' => json_encode($record['extra']),
			'formatted' => $record['formatted'],
		));
	}

	private function initialize()
	{
		$this->pdo->exec(<<<CREATE

CREATE TABLE IF NOT EXISTS
	monolog
(
	time DATETIME,
	channel VARCHAR(255),
	level INTEGER,
	level_name VARCHAR(255),
	message LONGTEXT,
	context LONGTEXT,
	extra LONGTEXT,
	formatted LONGTEXT
)

CREATE
		);

		$this->statement = $this->pdo->prepare(<<<INSERT

INSERT INTO
	monolog
(
	time,
	channel,
	level,
	level_name,
	message,
	context,
	extra,
	formatted
)
VALUES
(
	:time,
	:channel,
	:level,
	:level_name,
	:message,
	:context,
	:extra,
	:formatted
)

INSERT
		);

		$this->initialized = true;
	}
}