code: @Override
      public QOrderBySection appendSQL(final SQLSelect _select)
          throws EFapsException
      {
          _select.addPart(SQLPart.ORDERBY);
          boolean first = true;
          for (final AbstractQPart part : this.parts) {
              if (first) {
                  first = false;
              } else {
                  _select.addPart(SQLPart.COMMA);
              }
              part.appendSQL(_select);
          }
          return this;
      }
docs: {@inheritDoc}