I have a table where the the parent object has an optional many-to-one relationship. The problem is that the table is setup to default the fkey column to 0. When selecting, using fetch="join", etc-- the default of 0 on the fkey is being used to try over and over to select from another table for the ID 0. Of course this doesn't exist, but how can I tell Hibernate to treat a value of 0 to be the same as NULL-- to not cycle through 20+ times in fetching a relationship which doesn't exist? <many-to-one name="device" lazy="false" class="Device" not-null="true" access="field" cascade="none" not-found="ignore"> <column name="DEVICEID" default="0" not-null="false"/>