docs: public String getSQLFilter(String strSeekSign, String strCompare, boolean bComparison) 
      {
          if (strCompare == null)
          { // Use the current field value
              Boolean bField = (Boolean)this.getData(); // Get the physical data
              if (bField != null)
              {
                  boolean bValue = bField.booleanValue();
                  if (bValue == false)
                      strCompare = SQLFALSE;
                  else
                      strCompare = SQLTRUE;
              }
          }
          return super.getSQLFilter(strSeekSign, strCompare, bComparison);
      }