Question

I have the following classes which I would like to map using NHibernate

class User
{
    long Id {get; set;}
    IList<UserPassword> OldPasswords {get; set}
}

class UserPassword
{
    long UserId {get; set;}
    string Password {get; set;}
    DateTime CreateDtm {get; set;}
}

In the UserPassword table in the database (Oracle) UserId, Password and CreateDtm are a composite key (I cant change this)

At present my mapping files look like

<hibernate-mapping assembly="DomainEntities" namespace="DomainEntities.Models" xmlns="urn:nhibernate-mapping-2.2">

  <class name="User" table="USERS" lazy="true" >
    <id name="Id">
      <column name="USER_ID" sql-type="NUMBER" not-null="true" unique="true"/>
      <generator class="identity"/>
    </id>

    <bag name="OldPasswords" cascade="all" inverse="true">
      <key column="USER_ID" not-null="true" />
      <one-to-many class="UserPassword" />
    </bag>

  </class>
</hibernate-mapping>

<hibernate-mapping assembly="DomainEntities" namespace="DomainEntities.Models" xmlns="urn:nhibernate-mapping-2.2">

  <class name="UserPassword" table="USER_PASSWORDS" lazy="true" >

    <composite-id>
      <key-property name="UserId" column="USER_ID" />
      <key-property name="Password" column="OLD_PASSWORD" />
      <key-property name="CreateDtm" column="CREATE_DATE" />
    </composite-id>

  </class>

</hibernate-mapping>

When querying for the user object, its loading the user passwords correctly, however, I cant add or remove a new password to the list.

I have tried adding in a mapping on the User object, but when trying to commit the transaction, its thrown an exception on an invalid array index for the CreateDtm. I suspect this is because of the composite key.

Am I missing something in my mapping, or is this a scenario that just cant be done?

Answer 1

I was missing the tag in the composite id.

The composite-id now looks like

<composite-id> 
  <key-many-to-one name="User" column="USER_ID" lazy="proxy" class="User" /> 
  <key-property name="Password" column="OLD_PASSWORD" /> 
  <key-property name="CreateDtm" column="CREATE_DATE" /> 
</composite-id> 

The other part to this problem, was the cascade mode, on the parent. I needed to set cascade to “add-delete-orphan” to delete the items removed from the collection.