Constructs a Query object.
DatabaseConnection $connection: Database connection object.
array $options: Array of query options.
public function __construct(DatabaseConnection $connection, $options) {
$this->uniqueIdentifier = uniqid('', TRUE);
$this->connection = $connection;
$this->connectionKey = $this->connection
->getKey();
$this->connectionTarget = $this->connection
->getTarget();
$this->queryOptions = $options;
}