Hello everyone,
I have the following weird problem with Hibernate's session.update(...) method.
I store a hierarchy of folders to the database. Each folder has a parent object (can be null) and a Set of child folders.
My mapping file looks like this:
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>
<class name="test.Folder" table="FOLDERS">
<id name="id" type="long" access="field">
<column name="FOLDER_ID" />
<generator class="native" />
</id>
<set name="childFolders" table="FOLDERS" lazy="false" inverse="true" cascade="all">
<key column="PARENT_FOLDER_ID" not-null="false"></key>
<one-to-many class="test.Folder" />
</set>
<many-to-one name="parentFolder" column="PARENT_FOLDER_ID" />
<property name="name" column="FOLDER_NAME" />
<property name="rootFolder" column="IS_ROOT_FOLDER" type="boolean" not-null="true" />
<property name="path" column="FOLDER_PATH" />
<property name="type" column="FOLDER_TYPE" />
<property name="fullPath" column="FULL_PATH" unique="true" not-null="true" />
</class>
</hibernate-mapping>
Now, loading the folders from the database works perfectly. All the attributes are set and the hierarchy is correct.
BUT if I call
Code:
session.update(folder)
(in a new session) on a folder that has subfolders, a JDBC exception is thrown (duplicate entry).
Quote:
java.sql.SQLException: null, message from server: "Duplicate entry 'kuk2/kuki2' for key 2"
After the exception is thrown, the child folder also has id=0 (although it had id=4 before).
So, from my observation, the following is happening (not 100% sure though):
- session.update(parentFolder) updates the parent correctly but makes its child folder transient (sets id=0)
- Hibernate then tries to persist the child folder. Since id=0, it does an INSERT instead of an UPDATE
- Since the folder already exists in database, I get a duplicate entry exception because the attribute "fullPath" is unique and not-null.
Note: If folder has no subfolders and session.update(folder) is executed, everything works alright.
Can someone explain what's going on here? I already tried to remove the cascade="all" attribute in the mapping file but that had no effect.
While searching for a solution, I found this:
http://stackoverflow.com/questions/2784 ... e-children.. which lead me to
http://opensource.atlassian.com/project ... e/HHH-3332.. which again lead me to
http://opensource.atlassian.com/project ... e/HHH-5855 which doesn't seem to be solved yet.
Is there a workaround for this?
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