How to build an RWDBCriterion with dynamic restrictions

void main() {
	RWDBManager::setErrorHandler(errorHandler);

// FILL IN CONNECTION PARAMETERS!!
	RWDBDatabase db = RWDBManager::database(params);

	RWDBTracer &tracer = db.tracer();
	tracer.setOn(RWDBTracer::SQL);
	tracer.stream(cout);

	// Get a table and a selector
	RWDBTable tbl = db.table("test1");

	RWDBSelector sel = db.selector();
	// set the select list
	sel << tbl["id"];

	// Build an RWDBCriterion from RWDBExpr's and data read from file
	RWCString f;
	ifstream in("test.data");

	RWDBExpr expr1(tbl["name"]);
	RWDBCriterion crit1, crit2;
	f.readToken(in);
	if (!f.isNull()) {
		crit1 = expr1 == f.data();
		f.readToken(in);

		while (!f.isNull()) { // have another token
			crit2 = expr1 == f.data();
			crit1 = crit1 || crit2;
			f.readToken(in);
		}
	}
	sel.where(crit1);
	RWDBReader rdr = sel.reader();
	while(rdr()) 
		cout << "a row" << endl;
}