Map in another Map - how must the mapping file look like?

SebiB90 · **Joined:** Sat Mar 10, 2007 6:20 pm **Posts:** 2

Hi,
i have already written in the german forum, but i don´t know whether i get there an answer, so i want to ask here.

I have a class with a Map and the values of the map are also maps. The java code looks like this:

Code:

private TreeMap<Integer, TreeMap<Integer, Subject>> timetable = new TreeMap<Integer, TreeMap<Integer, Subject>>();

My Problem is that i don´t know what i have to write in the mapping file.

Code:

<?xml version="1.0"?> 
<!DOCTYPE hibernate-mapping PUBLIC 
"-//Hibernate/Hibernate Mapping DTD 3.0//EN" 
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> 

<hibernate-mapping package="schoolplaner"> 
  <class name="Timetable" table="TIMETABLE"> 
    <id name="id" column="TIMETABLE_ID"> 
      <generator class="native"/> 
    </id> 
    <property name="effectivWith" type="calendar"/> 
    <map name="timetable" table="TimetableSubjects"> 
      <key column="id"/> 
      <map-key type="integer"/> 
      <!-- ??? --> 
    </map> 
  </class> 
</hibernate-mapping>

This is my mapping file. Normally you write "element" or "one/many-to-many" after the map-key, but what do i have to write when the element is a map?

I hope you have understood me. My english is not very good.

Thank you in advance.
SebiB90

christian · **Posted:** Sun Mar 11, 2007 11:11 am

Collections in Collections are not supported. If you hit this limitation it's usually an indicator of a wrong domain model that will be a nightmare to use.