Indexed Collections

[Ruchika Kapoor]

I'm using map to retrieve object graph from database. The problem is while retrieving I'm getting the save value even though I'm getting different keys on each iteration.

My Schema is

TB_EVENTS
---------------------------------------------------------
IDNUMBER
NAMEVARCHAR
START_DATEDATE
DURATIONNUMBER


TB_SPEAKERS_LIST
---------------------------------------------------------
EVENT_IDNUMBER
NAMEVARCHAR
EVENT_INDEXVARCHAR


Event.hbm.xml
---------------------------------------------------------
<class name="Event" table="TB_EVENTS">
<id name="eventid" column="ID" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="name">
<column name="NAME" />
</property>
<property name="startDate">
<column name="START_DATE" />
</property>
<property name="duration">
<column name="DURATION" />
</property>

<map name="speakers" cascade="all" fetch="join">
<key column="EVENT_ID"/>
<map-key column="EVENT_INDEX" type="string"/>
<one-to-many class="Speakers"/>
</map>
</class>
</hibernate-mapping>


Speakers
---------------------------------------------------------
<class name="Speakers" table="TB_SPEAKERS_List">
<id name="eventid" column="EVENT_ID" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="name">
<column name="NAME" />
</property>
</class>
</hibernate-mapping>


Class File
---------------------------------------------------------

Event event=(Event)session.load(Event.class, new Integer("1"));
System.out.println("Event Name: "+event.getName());

Map map=event.getSpeakers();
Iterator itr=map.entrySet().iterator();
System.out.println("*************************");
Speakers speaker=null;
while(itr.hasNext()){
Map.Entry mapEntry=(Map.Entry)itr.next();
System.out.println("Event Index: "+mapEntry.getKey());
speaker=(Speakers)mapEntry.getValue();
System.out.println("Name: "+speaker.getName());
System.out.println("*************************");
}
txn.commit();



=========================

The query generated is

select event0_.ID as ID1_, event0_.NAME as NAME0_1_, event0_.START_DATE as START3_0_1_, event0_.DURATION as DURATION0_1_, speakers1_.EVENT_ID as EVENT1_3_, speakers1_.EVENT_INDEX as EVENT3_3_, speakers1_.EVENT_ID as EVENT1_0_, speakers1_.NAME as NAME1_0_ from TB_EVENTS event0_, TB_SPEAKERS_List speakers1_ where event0_.ID=speakers1_.EVENT_ID(+) and event0_.ID=?

Which is giving correct results when I executed it manually. Please help me figure out this problem.

Thanks,
Ruchika

[Ruchika Kapoor]

Anybody there. Please send some response.

[Mark Spritzler]

Can you explain your problem in a little more detail? At this point, I am not understanding what the problem is.

Also, there is a CODE button below the Add Reply button that will add CODE tags where you can paste your mappings and code, and it will retain all the indentation, so it is readable. Right now it has no indentation and is very difficult to read.

Thanks

Mark

[Ruchika Kapoor]

Mark,

I've written a piece of code which is using Map. Well, when I try to save objects, this code works fine but now when I try to retrieve records, it returns me Event object. When I retrieve Speaker and cast it to Map, it returns keys but it returns the same value twice as value even for different keys. The output I'm getting:
--------------------------------------------------------------

   
Event Name: AOL
*************************
Event Index: speaker2
Name: Neha
*************************
Event Index: speaker1
Name: Neha
*************************
 

The code is:

 
[B]Event.hbml.xml File[/B]
 
<hibernate-mapping package="com.CollectionsUsedInHibernate.map">
<class name="Event" table="TB_EVENTS">
<id name="eventid" column="ID" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="name">
           <column name="NAME" />
    </property>
    <property name="startDate">
           <column name="START_DATE" />
    </property>
    <property name="duration">
           <column name="DURATION" />
    </property>
<map name="speakers" cascade="all" fetch="join">
<key column="EVENT_ID"/>
<map-key column="EVENT_INDEX" type="string"/>
<one-to-many class="Speakers"/>
</map>
</class>
</hibernate-mapping>
 
[B]Speakers.hbm.xml File[/B]
 
<hibernate-mapping package="com.CollectionsUsedInHibernate.map">
<class name="Speakers" table="TB_SPEAKERS_List">
<id name="eventid" column="EVENT_ID" unsaved-value="0">
<generator class="increment"/>
</id>
<property name="name">
           <column name="NAME" />
    </property>   
</class>
</hibernate-mapping>
 
[B]Java Class [/B]
 
public static void main(String[] args) {
SessionFactory sessionFactory = new Configuration().configure()
.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction txn = session.beginTransaction();
try {

//Record Insertion is working fine.
/*
Event event=new Event();
event.setName("AOL");
event.setDuration(5);
event.setStartDate(java.sql.Date.valueOf("2008-5-5"));
Speakers speaker1=new Speakers();
speaker1.setName("Ruchika");
Speakers speaker2=new Speakers();
speaker2.setName("Anjali");
Speakers speaker3=new Speakers();
speaker3.setName("Neha");
Map speakers = new HashMap();
speakers.put("speaker1", speaker1);
speakers.put("speaker2", speaker2);
speakers.put("speaker2", speaker3);
event.setSpeakers(speakers);
session.save(event);
*/
Event event=(Event)session.load(Event.class, new Integer("1"));
System.out.println("Event Name: "+event.getName());
Map map=event.getSpeakers();

Iterator itr=map.entrySet().iterator();
System.out.println("*************************");
Speakers speaker=null;

while(itr.hasNext()){
Map.Entry mapEntry=(Map.Entry)itr.next();
System.out.println("Event Index: "+mapEntry.getKey());
speaker=(Speakers)mapEntry.getValue();
System.out.println("Name: "+speaker.getName());
System.out.println("*************************");
}
txn.commit();


} catch (Exception e) {
 
System.out.println("Exception Occured " + e.getMessage());
e.printStackTrace();
 
} finally {
session.flush();
session.close();
}
}

Thanks,
Ruchika

[Mark Spritzler]

Off the top of my head I am not seeing anything.

Anyone else see something I am missing (probably a real simple thing, those are the ones that I always overlook). If not, we can try some things

1. Print out the Map just after save() but before your call to load()
2. commit and close your transaction and session right after save, then open a new Session/transactiona and do a load(), to see what happens


You are sure the save is creating three records all with different speaker names in the speaker table?

Mark

[Ruchika Kapoor]

Mark,

I tried printing out the value, and you know it displays the values correctly. But then I created a all together a new session and loaded the object, but this time I'm getting the same results.

Am not really able to figure out the real problem. Values are being saved correctly, stored correctly and even keys are retrieved correctly. Then where am I going wrong ?

Thanks,
Ruchika