How to save this type of data ?

vipcowrie · **Joined:** Thu Sep 04, 2003 2:52 am **Posts:** 29

HI all,
I have a problem in saving data using hibernate.

I have a data class:

Code:

class Data {
  Value value;
}

class Value {
  List values;//[b] this list in turn contains a list ,which contains real data[/b]}

Now ,I have to save the Data,how can I do this ? anyone can help me ?

cowrie

vipcowrie · **Joined:** Thu Sep 04, 2003 2:52 am **Posts:** 29

Actually this is a problem in saving a two dimensional array data type.

g1friend · **Joined:** Thu Sep 18, 2003 1:50 am **Posts:** 17

Here is the mapping for that,

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
<class name="com.abcd.Value" table="value">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<bag name="values">
<key column="value_id"/>
<one-to-many class="com.abcd.Value"/>
</bag>
</class>

<class name="com.translogicsys.persistence.Data" table="data">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<many-to-one name="value" class="com.abcd.Value"/>
</class>
</hibernate-mapping>

- Jeevan (G1)
-------------------------------------------------------

vipcowrie wrote:

HI all,
I have a problem in saving data using hibernate.

I have a data class:

Code:

class Data {
  Value value;
}

class Value {
  List values;//[b] this list in turn contains a list ,which contains real data[/b]}

Now ,I have to save the Data,how can I do this ? anyone can help me ?

cowrie

vipcowrie · **Joined:** Thu Sep 04, 2003 2:52 am **Posts:** 29

class Result {
RequestResult[] results;
}

class RequestResult {
List requestResultObjs; //// This List is really a table ,
//// Its row is a list
//// its cell is all of type: RequestResultObj
}

class RequestResultObj {
Value value;
}

class Value {
int i;
String desc;
}

I must store Result. It's challeging,isn't it? who can solve this problem?

g1friend · **Joined:** Thu Sep 18, 2003 1:50 am **Posts:** 17

Here is my solution to the problem statement you've given:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
<class name="com.abcd.Request" table="request">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<array name="results">
<key column="request_id"/>
<index column="resultindex" type="int" />
<one-to-many class="com.abcd.RequestResult" />
</array>
</class>
<class name="com.abcd.RequestResult" table="requestresult">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<list name="requestResultObjs">
<key column="requestresult_id"/>
<index column="objindex" type="int" />
<one-to-many class="com.abcd.RequestResultObject" />
</list>
</class>
<class name="com.abcd.RequestResult" table="requestresult">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<list name="requestResultObjs">
<key column="requestresult_id"/>
<index column="objindex" type="int" />
<one-to-many class="com.abcd.RequestResultObject" />
</list>
</class>
<class name="com.abcd.RequestResultObject" table="requestresultobject">
<id name="id" type="int" unsaved-value="0">
<generator class="identity"/>
</id>
<many-to-one name="value" class="com.abcd.Value"/>
</class>
</hibernate-mapping>

As I'm new to Hibernate, I'm trying to learn it with the help of this forum. Anybody who has time, please validate the solution.

Thanks,

- Jeevan (G1)

********************************************************

vipcowrie wrote:

class Result {
RequestResult[] results;
}

class RequestResult {
List requestResultObjs; //// This List is really a table ,
//// Its row is a list
//// its cell is all of type: RequestResultObj
}

class RequestResultObj {
Value value;
}

class Value {
int i;
String desc;
}

I must store Result. It's challeging,isn't it? who can solve this problem?

vipcowrie · **Joined:** Thu Sep 04, 2003 2:52 am **Posts:** 29

thanks , I am surprised that you are just a newer to hibernate. I would test your solutions in my project. But I think it's ok.

vipcowrie · **Joined:** Thu Sep 04, 2003 2:52 am **Posts:** 29

I have test this mapping,but I've got some exceptions.such as follows:
----------------------------

net.sf.hibernate.MappingException: No persister for: java.util.ArrayList

the code is :

Code:

    RequestResult rrTable = new RequestResult();
    rrTable.addRRO(rro1);
    rrTable.addRRO(rro2);
    rrTable.addRRO(rro3);
    rrTable.addRRO(rro4);
    rrTable.addRRO(rro5);
    List requestResultList = new ArrayList();
    requestResultList.add(rrTable);

    pr.setRequestResult(requestResultList);
    try {
      pdao.insertPollingResult(pr);
    }
    catch (HibernateException ex) {
      ex.printStackTrace();
    }

g1friend · **Joined:** Thu Sep 18, 2003 1:50 am **Posts:** 17

The reason for the exception is in one of the collections you're trying to save contains objects of type ArrayList. That ie, that collection is again contains a collection ArrayList which is not known to Hibernate. The reason could be:

- either the requestResult property in the class related to "pr" is ArrayList
- or atleast on of the rro* series of objects is of type ArrayList.

- Jeevan (G1)