/** INTERNAL: Print SQL onto the stream, using the ExpressionPrinter for context */
  public void printSQL(ExpressionSQLPrinter printer) {
    if (isAttribute()) {
      printer.printField(getAliasedField());
    }

    // If the mapping is a direct collection then this falls into a gray area.
    // It must be treated as an attribute at this moment for it has a direct field.
    // However it is not an attribute in the sense that it also represents a foreign
    // reference and a mapping criteria has been added.
    // For bug 2900974 these are now handled as non-attributes during normalize but
    // as attributes when printing SQL.
    //
    if ((!isAttribute()) && (getMapping() != null) && getMapping().isDirectCollectionMapping()) {
      DirectCollectionMapping directCollectionMapping = (DirectCollectionMapping) getMapping();

      // The aliased table comes for free as it was a required part of the join criteria.
      TableExpression table =
          (TableExpression) getTable(directCollectionMapping.getReferenceTable());
      DatabaseTable aliasedTable = table.aliasForTable(table.getTable());
      DatabaseField aliasedField = (DatabaseField) directCollectionMapping.getDirectField().clone();
      aliasedField.setTable(aliasedTable);
      printer.printField(aliasedField);
    }

    if ((getMapping() != null) && getMapping().isNestedTableMapping()) {
      DatabaseTable tableAlias = aliasForTable(new NestedTable(this));
      printer.printString(tableAlias.getName());
    }
  }
 /**
  * INTERNAL: writes the first field from each of the owned tables, used for fine-grained
  * pessimistic locking.
  */
 protected void writeForUpdateOfFields(
     ExpressionSQLPrinter printer, SQLSelectStatement statement) {
   for (Iterator iterator = getForUpdateOfFields().iterator(); iterator.hasNext(); ) {
     DatabaseField field = (DatabaseField) iterator.next();
     if (printer.getPlatform().shouldPrintAliasForUpdate()) {
       writeAlias(printer, field, statement);
     } else {
       writeField(printer, field, statement);
     }
   }
 }