$sql
$sql : \Query\Driver\SQL_Interface
Reference to sql class
Base Database class
Extends PDO to simplify cross-database issues
$table : \Query\Table\Table_Builder
Reference to table_builder class
get_sql() : \Query\Driver\SQL\SQL_Interface
Get the SQL class for the current driver
get_util() : \Query\Driver\Util\Abstract_Util
Get the Util class for the current driver