fail to create unique constraint with hibernate annotation in a postgres database

Question

Im using hibernate, postgres 9.1, and i'm trying to add a unique constraint via hibernate annotation (not adding explicitly in the database)

However, db ignores the unique annotation and doesn't create the constraint. I also tried add the contraint in the @Table annotation but failed too

@Entity
public class Person implements Serializable {   

 @Id
 @Column(insertable=false, updatable=false)
 @Type(type="java.lang.Long")
 @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="PERSON_SEQ")
 @SequenceGenerator(name="PERSON_SEQ", sequenceName="PERSON_SEQ", allocationSize=1)
 private Long id;


 @Column(unique=true)
 private String username;
}

hibernate.cfg.xml

<hibernate-configuration>
<session-factory>

    <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
    <property name="hibernate.connection.url">jdbc:postgresql://localhost:5432/Test1</property>
    <property name="hibernate.connection.username">postgres</property>
    <property name="hibernate.connection.password">postgres</property>
    <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>

    <property name="hbm2ddl.auto">update</property>

</session-factory>

the constraint is not passed to the db. Also, i test it and it let me create duplicate usernames — user711189
– user711189, Commented Jan 8, 2012 at 9:29

Timothy Klim · Accepted Answer · 2012-02-11 21:09:34Z

1

Just set property "hbm2ddl.auto" to "create" and hibernate will recreate table with unique column.

answered Feb 11, 2012 at 21:09

Timothy Klim

1,27716 silver badges25 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

fail to create unique constraint with hibernate annotation in a postgres database

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related