docs: public int getCodeKeyArea()
      {
          int iTargetKeyArea = 0;   // Key 0 cannot be the code key
          for (int i = this.getKeyAreaCount() - 1; i >= 0 ; i--)
          {
              KeyArea keyArea = this.getKeyArea(i);
              if (keyArea.getUniqueKeyCode() == DBConstants.SECONDARY_KEY)
                  iTargetKeyArea = i;
              if (iTargetKeyArea == 0)
                  if (keyArea.getUniqueKeyCode() == DBConstants.NOT_UNIQUE)
                      if (keyArea.getField(0).getDataClass() == String.class)
                          iTargetKeyArea = i; // Best guess if no secondary
          }
          return iTargetKeyArea;
      }