Error inserting into one-to-many associations

Prakash · **Joined:** Wed Sep 08, 2004 5:09 pm **Posts:** 3

Hibernate version:2.1

Problem scenario:

We have a Parent object which has a one-to-many relation with the Child object.

In the Parent.hbm.xml file we mentioned that one-to-many relation with the Child object.
Child object has a Parent_ID parameter which maps to Parent's _Id. And in the Child table Parent_ID column is NOT NULL type.

In the Java Bean of Parent.java we have Child as List datamember. i.e something like

Code:

public class Parent
{
           java.long.Long  _Id;
          java.lang.String  _childName;
           ......
           ......
           ......
           List _childList;
    
}

public class Child
{
       java.long.Long _Id;
       java.lang.String  _name;
       java.math.BigDecimal _parentId;
           ......
           ......
           ......
}


Now, I create a Parent object like

parent = new Parent();

parent.setName("parent");

Child child1 = new Child();
child1.setName( "child1");

List childList = new List();
childList.add( child1 );

parent.setChildList( childList );
parent.store(); // THIS GIVES ERROR Parent_Id cannot be NULL

THE ABOVE CODE DOESN'T WORK

Now, when I stoore the Parent object , then what I am expecting is Parent get's a unique Id when it gets inserted into the Parent table, and when it should cacadingly insert the children too with the corresponding Parent_Id.

But, this is not happening, it is throwing me an error saying that NULL cannot inserted into Parent_Id column in the CHILD table .

So, when I tried changing the code a little bit, like

Code:

parent = new Parent();

parent.setName("parent");

parent.store();

Long parentId = parent.getId();

Child child1 = new Child();
child1.setName( "child1");
child.setParentId( parentId );

List childList = new List();
childList.add( child1 );

parent.setChildList( childList );

parent.store(); //THIS STORES IT SUCCESSFULLY INTO CHILD TABLE

I dont understand why the first code snippet doesn't work. Any help is greatly appreciated.
This is impacting our project so, please respond ASAP.

emmanuel · **Posted:** Fri Sep 10, 2004 11:24 am

Prakash wrote:

This is impacting our project so, please respond ASAP.

This is the best sentence not to have any help.
http://www.hibernate.org/hib_docs/reference/en/html_single/#collections-bidirectional

anthony · **Posted:** Fri Sep 10, 2004 12:14 pm

Quote:

This is impacting our project so, please respond ASAP.

because it is impacting your project we advice you to get some support, here the community don't care about project, just about people, challenge and fun ;)

Note: this is not a rude answer, just an advice

check this http://www.hibernate.org/149.html

ssuravarapu · **Joined:** Fri Sep 10, 2004 10:53 pm **Posts:** 3

Prakash wrote:

Hibernate version:2.1
I dont understand why the first code snippet doesn't work. Any help is greatly appreciated.
This is impacting our project so, please respond ASAP.

You did not post your mapping files. Make sure in the parent.hbm.xml file, while setting the one-to-many relation mapping with child you have cascade property set to "all". After doing this try running the code that was throwing errors.

Prakash · **Joined:** Wed Sep 08, 2004 5:09 pm **Posts:** 3

ssuravarapu wrote:

Prakash wrote:

Hibernate version:2.1
I dont understand why the first code snippet doesn't work. Any help is greatly appreciated.
This is impacting our project so, please respond ASAP.

You did not post your mapping files. Make sure in the parent.hbm.xml file, while setting the one-to-many relation mapping with child you have cascade property set to "all". After doing this try running the code that was throwing errors.

Sorry, I forgot to mention that I have cascade="all" in the association entry. Then also the same problem was arising.

ssuravarapu · **Joined:** Fri Sep 10, 2004 10:53 pm **Posts:** 3

Prakash wrote:

Sorry, I forgot to mention that I have cascade="all" in the association entry. Then also the same problem was arising.

Can you post your mapping files?

Prakash · **Joined:** Wed Sep 08, 2004 5:09 pm **Posts:** 3

ssuravarapu wrote:

Can you post your mapping files?

Prakash wrote:

EibParent.hbm.xml
-------------------------------------------------------
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping package="com.xyz.abc">
<class name="EibParent" table="EIB_PARENT">

<id name="id" column="ID" type="java.lang.Long" unsaved-value="null">
<generator class="seqhilo">
<param name="sequence">EIB_PARENT_SEQ</param>
<param name="max_lo">1</param>

</generator>
</id>

<property name="categoryId" column="CATEGORY_ID" type="java.math.BigDecimal" />
<property name="name" column="NAME" type="java.lang.String" />

<bag name="Child1List" lazy="false" inverse="true" cascade="all">
<key>
<column name="PARENT_ID"/>
</key>
<one-to-many class="EibChild1"/>
</bag>
<bag name="Child2List" lazy="false" inverse="true" cascade="all">
<key>
<column name="PARENT_ID"/>
</key>
<one-to-many class="EibChild2"/>
</bag>
<bag name="Child3List" lazy="false" inverse="true" cascade="all">
<key>
<column name="PARENT_ID"/>
</key>
<one-to-many class="EibChild3"/>
</bag>

</class>

</hibernate-mapping>

----------------------------------------------------------------------------------------

EibChild2.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping package="com.xyz.abc">
<class name="EibChild2" table="EIB_CHILD2_V">

<id name="id" column="ID" type="java.lang.Long" unsaved-value="null">
<generator class="seqhilo">
<param name="sequence">EIB_CHILD_SEQ</param>
<param name="max_lo">10</param>

</generator>
</id>

<property name="parentId" column="PARENT_ID" type="java.math.BigDecimal" />
<property name="name" column="NAME" type="java.lang.String" />

</class>

</hibernate-mapping>

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