SQL; // <------------- THIS

	Sqlite3Session sqlite3;
	if(!sqlite3.Open(ConfigFile("simple.db"))) {
		Exclamation("Can't create or open database file\n");
		return;
	}

	SQL = sqlite3;//<------------ And THIS

struct AppSql : Sql {
	void   operator=(SqlSource& s) { Assign(s); }
	void   Detach()                { Sql::Detach(); }
	AppSql() : Sql(NULLSQL) {}
};
AppSql& AppCursor();
#define SQL AppCursor()

Sql::Sql(const char *stmt) {
	cn = SQL.GetSession().CreateConnection();
	SetStatement(stmt);
}

Sqlite3Session m_session;
bool good_conn = m_session.Open("my_database_file.db");
Sql sql(m_session); //define Sql object to act on Session object m_session.

void SQLApp::Query()
{
	SqlBool where;
	SqlSet borrowed = Select(BOOK_ID).From(BORROW_RECORD).Where(IsNull(RETURNED));
	if(query.status == 1)
		where = ID != borrowed;
	if(query.status == 2)
		where = ID == borrowed;
	SqlBool bdate;
	if(!IsNull(query.borrowed_from))
		bdate = BORROWED >= ~query.borrowed_from;
	if(!IsNull(query.borrowed_to))
		bdate = bdate && BORROWED <= ~query.borrowed_to;
	if(!bdate.IsEmpty())
		where = where && ID == Select(BOOK_ID).From(BORROW_RECORD).Where(bdate);
	book.Query(where);
}

// Build query:
SqlSet queryName1 = Select(NAME).From(NAME_TABLE1);
SqlBool nameIsSame = In(NAME,queryName1);
// Finish building and run query:
sql * Select(NAME).From(NAME_TABLE2).Where(nameIsSame);