final List<ColumnNameType> cnts = new ArrayList<ColumnNameType>();
for (final Expression expr : choosenExprs) {
// first to determine the type, we use the first column for that
final TypeConversion tc = getTC(expr);
// attach the TypeConversion
final String exprStr = ParserUtil.getStringExpr(expr);
final ColumnNameType cnt = new ColumnNameType(exprStr, tc);
cnts.add(cnt);