public List<EventColumn> getUpdatedKeys() {
        List<EventColumn> columns = new ArrayList<EventColumn>();
        for (EventColumn column : this.keys) {
            if (column.isUpdate()) {
                columns.add(column);
            }
        }

        return columns;
    }
public List < EventColumn > getUpdatedKeys ( ) { List < EventColumn > columns = new ArrayList < EventColumn > ( ) ; for ( EventColumn column : this . keys ) { if ( column . isUpdate ( ) ) { columns . add ( column ) ; } } return columns ; }
返回所有变更的主键字段