code: @Override
      public int append2SQLSelect(final Type _type,
                                  final SQLSelect _select,
                                  final int _tableIndex,
                                  final int _colIndex)
          throws EFapsException
      {
          if (this.attribute == null) {
              this.attribute = _type.getAttribute(this.attrName);
          }
          if (this.attribute == null) {
              AttributeValueSelect.LOG.error("Could not get an attribute with name '{} 'for type: '{}'", this.attrName,
                              _type);
              throw new EFapsException(AttributeValueSelect.class, "appendNoAttribute");
          }
          int ret = 0;
          for (final String colName : this.attribute.getSqlColNames()) {
              _select.column(_tableIndex, colName);
              getColIndexs().add(_colIndex + ret);
              ret++;
          }
          // in case of dependencies for the attribute they must be selected also
          for (final Attribute attr : this.attribute.getDependencies().values()) {
              for (final String colName : attr.getSqlColNames()) {
                  _select.column(_tableIndex, colName);
                  getColIndexs().add(_colIndex + ret);
                  ret++;
              }
          }
          return ret;
      }
docs: {@inheritDoc}