public function clean($delay = self::CLEAN_DELAY)
    {
        $delay += self::CACHE_TIME;
        $query = $this->pdo->prepare(<<<SQL
DELETE FROM robotstxt__cache1
WHERE nextUpdate < (UNIX_TIMESTAMP() - :delay);
SQL
        );
        $query->bindValue('delay', $delay, \PDO::PARAM_INT);
        return $query->execute();
    }
public function clean($delay = self::CLEAN_DELAY)
    {
        $delay += self::CACHE_TIME;
        $query = $this->pdo->prepare(<<<SQL
DELETE FROM robotstxt__cache1
WHERE nextUpdate < (UNIX_TIMESTAMP() - :delay);
SQL
        );
        $query->bindValue('delay', $delay, \PDO::PARAM_INT);
        return $query->execute();
    }
public function clean ( $ delay = self :: CLEAN_DELAY ) { $ delay += self :: CACHE_TIME ; $ query = $ this -> pdo -> prepare ( <<<SQL
DELETE FROM robotstxt__cache1
WHERE nextUpdate < (UNIX_TIMESTAMP() - :delay);
SQL ) ; $ query -> bindValue ( 'delay' , $ delay , \ PDO :: PARAM_INT ) ; return $ query -> execute ( ) ; }
Clean the cache table

@param int $delay
@return bool
Clean the cache table