/**
   * INTERNAL: Returns the first field from each of the owned tables, used for fine-grained
   * pessimistic locking.
   */
  protected Vector getForUpdateOfFields() {
    Vector allFields = getFields();
    int expected = getTableAliases().size();
    Vector firstFields = new Vector(expected);
    DatabaseTable lastTable = null;
    DatabaseField field = null;
    int i = 0;

    // The following loop takes O(n*m) time.  n=# of fields. m=#tables.
    // However, in the m=1 case this will take one pass only.
    // Also assuming that fields are generally sorted by table, this will
    // take O(n) time.
    // An even faster way may be to go getDescriptor().getAdditionalPrimaryKeyFields.
    while ((i < allFields.size()) && (firstFields.size() < expected)) {
      field = (DatabaseField) allFields.elementAt(i++);
      if ((lastTable == null) || !field.getTable().equals(lastTable)) {
        lastTable = field.getTable();
        int j = 0;
        while (j < firstFields.size()) {
          if (lastTable.equals(((DatabaseField) firstFields.elementAt(j)).getTable())) {
            break;
          }
          j++;
        }
        if (j == firstFields.size()) {
          firstFields.addElement(field);
        }
      }
    }
    return firstFields;
  }
  /** Append the string containing the SQL insert string for the given table. */
  protected SQLCall buildCallWithoutReturning(AbstractSession session) {
    SQLCall call = new SQLCall();
    call.returnNothing();

    Writer writer = new CharArrayWriter(200);
    try {
      writer.write("INSERT ");
      if (getHintString() != null) {
        writer.write(getHintString());
        writer.write(" ");
      }
      writer.write("INTO ");
      writer.write(getTable().getQualifiedNameDelimited(session.getPlatform()));
      writer.write(" (");

      Vector fieldsForTable = new Vector();
      for (Enumeration fieldsEnum = getModifyRow().keys(); fieldsEnum.hasMoreElements(); ) {
        DatabaseField field = (DatabaseField) fieldsEnum.nextElement();
        if (field.getTable().equals(getTable()) || (!field.hasTableName())) {
          fieldsForTable.addElement(field);
        }
      }

      if (fieldsForTable.isEmpty()) {
        throw QueryException.objectToInsertIsEmpty(getTable());
      }

      for (int i = 0; i < fieldsForTable.size(); i++) {
        writer.write(
            ((DatabaseField) fieldsForTable.elementAt(i)).getNameDelimited(session.getPlatform()));
        if ((i + 1) < fieldsForTable.size()) {
          writer.write(", ");
        }
      }
      writer.write(") VALUES (");

      for (int i = 0; i < fieldsForTable.size(); i++) {
        DatabaseField field = (DatabaseField) fieldsForTable.elementAt(i);
        call.appendModify(writer, field);
        if ((i + 1) < fieldsForTable.size()) {
          writer.write(", ");
        }
      }
      writer.write(")");

      call.setSQLString(writer.toString());
    } catch (IOException exception) {
      throw ValidationException.fileError(exception);
    }
    return call;
  }