I've been doing Hibernate for all of maybe 2 months and I must say, it's been great once I've learned how to use it. I'm actually using Spring 2.0 also and it really eliminates alot of coding, especially code concerning transactions and sessions.

I have a User (see mapping below) that has a unique constraint in the database on username& mainclientid. When I do an update, I get constraint violation exception. I notice that it happens because Hibernate is doing an Insert, not an Update. I've read (and seen) that Hibernate actually does a delete, and an insert for accomplishing an update. Normally this isn't a problem as I don't have this additional constraint on any other tables I'm dealing with.

I read in HIbernate in Action, that you would define my constraint as a composite-id (p335), but in the mapping schema you can have either <id> or <composite-id>. I don't really want to use the composite-id in all my foreign key relationship, so eliminating the <id> isn't really an option.

So as a work around to my constrain violation, can I force Hibernate to update instead of delete/insert? I believe I can do nothing to force the delete before the insert.

This is my User mapping file<hibernate-mapping>
<class name="com.its.safer.app.domain.User" table="User">
<id name="userID" column="UserID">
<generator class="increment" />
</id>
<property name="username" column="UserName" />
<property name="password" column="Password" />
<property name="name" column="Name" />
<property name="mainClientID" column="MainClientID" />
<property name="callCenter" column="callCenter" />
<property name="invalidAttempts" column="InvalidLoginAttempts" />
<property name="locked" column="IsLocked" />
<property name="lastChangeDate" column="DateModified" />
<property name="lastLoginDate" column="lastLogin" />
<set name="groups" table="UserGroupMap" cascade="none" lazy="false">
<key column="UserID"/>
<many-to-many class="com.its.safer.app.bean.Group" column="UserGroupID"/>
</set>
<set name="userExtension" cascade="all" lazy="false">
<key column="UserID" />
<one-to-many
class="com.its.safer.app.bean.UserExtension" />
</set>

</class>
<query name="com.its.safer.app.domain.User.byUserNameAndMainClient">
<![CDATA[from User where userName = :userName and mainClientID = :mainClientID]]>
</query>
<query name="com.its.safer.app.domain.User.byMainClient">
<![CDATA[from User where mainClientID = :mainClientID]]>
</query>
</hibernate-mapping>

I am using Hibernate 3.0 with Spring 2.0 so I don't do anything with Session. I simply call getHibernateTemplate().update(user); My database is MySQL 5.0.


Thanks for any help I can get! I've been searching for several hours for a work around!

I'm trying to make an educated guess here without seeing the code snippet that does the update or the exception.

So you have a one-many relationship from the User table to the UserExtension table. I'd assume this is a bidirectional relationship. In a one-many relationship, usually the many side is the owner, in this case UserExtension.

So in the mapping file for User, you need to set inverse=true for userExtension. This tells Hibernate to ignore it (from the User side). The link will be handled from the UserExtension side.