SqlCol operator [] (const SqlId& id) const;

Select(ID, CUSTOMER[NAME], PRODUCT[QUANTITY])...

Select(ID, NAME.Of(CUSTOMER), QUANTITY.Of(PRODUCT))...

TABLE(CUSTOMER, CU)
END_TABLE

Select(CU[NAME], CU[AGE])
.From(CUSTOMER).As(CU) //of course As is not necessary here

Nametable Table,Pre(Nam) 

Nam:ID 
or 
Nam:Comment 

#include <Core/Core.h>
#include <Sql/Sql.h>

using namespace Upp;

struct CustomerTable
{
	const SqlId ID;
	const SqlId NAME;
	const SqlId AGE;
	
	operator SqlId()
	{
		return SqlId("CUSTOMER");
	}
	
	CustomerTable() :
	ID("CUSTOMER.ID"),
	NAME("CUSTOMER.NAME"),
	AGE("CUSTOMER.AGE")
	{}
};

CustomerTable CUSTOMER;
#define CUS CUSTOMER //alias

CONSOLE_APP_MAIN
{
	SqlSelect s = 
		::Select(CUSTOMER.NAME, CUSTOMER.AGE)
		.From(CUSTOMER)
		.Where(CUS.ID == 10);
		
	SqlStatement stmt = s;
	Cout() << stmt.GetText() << '\n';
}