@NaturalId and @Column(unique=true) annotations generate two unique constraints. -------------------------------------------------------------------------------- Key: HHH-4831 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-4831 Project: Hibernate Core Issue Type: Bug Components: annotations Affects Versions: 3.3.2 Reporter: Marcin Kuthan @NaturalId and @Column(unique=true) annotations generate two unique constraints. For the following column definition: {code} @Column(name = "dictionary_code", length = 256, nullable = false, unique = true) @org.hibernate.annotations.NaturalId public String getCode() { return code; } {code} Generated DDL for Mysql: {code} create table foo (entity_id bigint not null auto_increment, dictionary_code varchar(256) not null unique, primary key (entity_id), unique (dictionary_code)) ENGINE=InnoDB; {code} Generated DDL for Oracle: {code} create table foo (entity_id number(19,0) not null, dictionary_code varchar2(256 char) not null unique, primary key (entity_id), unique (dictionary_code)); {code} As a workaround I set unique=false in @Column annotation. The @NaturalId annotation processor must be aware of @Column annotation, IMHO. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://opensource.atlassian.com/projects/hibernate/secure/Administrators.... - For more information on JIRA, see: http://www.atlassian.com/software/jira