[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-4422) org.hibernate.test.annotations.EntityTest fails because DB2 does not support unique constraints on nullable columns

org.hibernate.test.annotations.EntityTest fails because DB2 does not support unique constraints on nullable columns ------------------------------------------------------------------------------------------------------------------- Key: HHH-4422 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-4422 Project: Hibernate Core Issue Type: Bug Components: annotations Reporter: Gail Badner Fix For: 3.5.0.Beta-1 Attachments: ANN-822.diff The following org.hibernate.test.annotations.EntityTest tests fail on DB2: testColumnUnique() testUniqueConstraint() DB2 does not support unique constraints on nullable columns. DB2 does support unique indexes on nullable columns, but only be 1 null value is allowed. (DB2 for z/OS does appear to allow multiple null values; is that a different dialect?) When DB2Dialect is used, Hibernate does not create unique constraints or indexes on nullable columns. This is why the expected constraint violations do not occur in the tests. The tests give an erroneous message "org.hibernate.TransactionException: Transaction not successfully started" because an attempt is made to rollback the transaction after it was successfully committed.