one-to-one problems

mosseri · **Joined:** Mon Mar 15, 2004 4:59 pm **Posts:** 3

Hello all,

Using Hibernate version 2.1.4, Postgres 7.3.4.

I have two hibernate objects:

First, Channel which has a native generator for its ID (named channelId) and a one-to-one relationship with Vouch, cascade all. Vouch has a foreign generator for its id (named vouchId) with generator-param property set to channel. Within Vouch I have a one-to-one relationship with Channel, cascade save-update.

Vouch.hbm.xml:

Code:

<id
            name="vouchId"
            column="vouchId"
            type="java.lang.Long"
        >
            <generator class="foreign">
                <param name="property">channel</param>
            </generator>
        </id>

        <one-to-one
            name="channel"
            class="Channel"
            cascade="save-update"
            outer-join="auto"
            constrained="true"
        />

Channel.hbm.xml:

Code:

<id
            name="channelId"
            column="channelId"
            type="java.lang.Long"
        >
            <generator class="native">
            </generator>
        </id>

        <one-to-one
            name="vouch"
            class="Vouch"
            cascade="all"
            outer-join="auto"
            constrained="false"
        />

Here is the test I am running:

Code:

Channel channel = new Channel();
channel = createChannel(channel);
   
Vouch vouch = new Vouch();
vouch.setChannel(channel);
vouch = createVouch(vouch);
   
deleteChannel(channel);

The deleteChannel fails b/c of a referential integrity error (the vouch never gets deleted first).

methods that are called (open and closing sesion removed within each method, also error catching removed):

Code:

public Channel createChannel(Channel channel) {
      session.save(channel);
      session.flush();
      session.refresh(channel);
      return channel;
}

public void deleteChannel(Channel channel) {
      session.delete(channel);
      session.flush();
}
   

The createVouch method is functionally identical to createChannel.

I tried using constrained, but that didn't work. What is actually happening is the channel's vouch reference isn't getting set when I do a createVouch with the vouch's channel reference set appropriately (vouch.channel ok, but channel.vouch null, vouch.getChannel.vouch is also null).

It doesn't appear to be setting up the reverse relationship appropriately. When I try to do a deleteChannel on the channel, it will orphan the vouch. If constrained is set and I try to deleteChannel, I get a referential integrity violation since it isn't deleting the vouch before the channel (no reference is set in channel to the appropriate vouch).

Any help would be greatly appreciated!

Mike

emmanuel · **Posted:** Wed Mar 17, 2004 10:07 am

Hibernate does not manage association in you java graph. It is your responsability to setOnetoOne both side when updating an already loaded object.