composite-key does not support null-values ------------------------------------------ Key: HHH-1109 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1109 Project: Hibernate Core Issue Type: Bug Affects Versions: 3.0.5 Environment: [org.hibernate.type.EmbeddedComponentType.hydrate(...)#425] Reporter: Holger Bartnick Attachments: componentType-fix-nullkey-compositekey.patch Original Estimate: 1 day Remaining Estimate: 1 day At present all legacy data with null-values in its composite-key could not be read properly by hibernate. While hibernate processes the resultset it returns null for that record and steps over to the next one. Think of a db-view, which combines two (or more) tables by outer-join. (that seems only necessary for crude legacy data indeed... but it´s not that unusual as you think) The workaround is to use a db-generated identifier for each view-record (ex. combining the nullable-id fields). It would be fine, if hibernate is not reliant on that. ;-) To allow having composite-keys with partly null-Values, you could think of moving the "unsaved-value"-attribute of the "composite-key"-tag to "key-property|key-many-to-one"-Tags...?! --- Mmmh... saw you´ve done something with "columnNullness" in ver 3.1beta2. Perhaps it is fixed in there... also seen on HB-613