I want to create a unique column "dtString" I have specified the unique="true" constraint in the hbm file but the generated ddl doesn't contain the unique constraint. What am I doing wrong?


Hibernate version:
version 2.1.4, 02. June 2004

Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >

<hibernate-mapping package="com.nokia.sspa.vobjects">
<class name="VObjectOthertypes" table="sspa_othertypes">

<id name="id" column="id" type="string">
<generator class="uuid.hex"/>
</id>

<property name="lastModified" unique="false" not-null="false" column="lastModified" />
<property name="modifierId" unique="false" not-null="false" column="modifierId" />
<property name="otherId" unique="false" not-null="true" type="string">
<column name="otherId" length="128"/>
</property>
<property name="dtShort" unique="false" not-null="true" column="dtShort" />
<property name="dtLong" unique="false" not-null="true" column="dtLong" />
<property name="dtInteger" unique="false" not-null="true" column="dtInteger" />
<property name="dtString" unique="true" not-null="true" type="string">
<column name="dtString" length="128"/>
</property>
<property name="dtBoolean" unique="false" not-null="true" column="dtBoolean" />
</class>

</hibernate-mapping>


Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:

Name and version of the database you are using:
postgres (PostgreSQL) 8.0.0beta4

The generated SQL (show_sql=true):
[schemaexport] create table sspa_othertypes (
[schemaexport] id VARCHAR(255) not null,
[schemaexport] lastModified TIMESTAMP,
[schemaexport] modifierId VARCHAR(255),
[schemaexport] otherId VARCHAR(128),
[schemaexport] dtShort INT2 not null,
[schemaexport] dtLong INT8 not null,
[schemaexport] dtInteger INT4 not null,
[schemaexport] dtString VARCHAR(128),
[schemaexport] dtBoolean BOOL not null,
[schemaexport] primary key (id)
[schemaexport] );

Debug level Hibernate log excerpt:

This is an old post, but as I spent hours searching, here's the solution just for the sake of completeness:

<property name="dtString" unique="true" not-null="true" type="string">
<column name="dtString" length="128"/>
</property>

if you specify an inner column tag and do not use the shorter form, the unique and not-null attributes have to be moved to the column tag:

<property name="dtString" type="string">
<column name="dtString" length="128" unique="true" not-null="true" />
</property>

SchemaExport does not warn you in the first case and simply does not create the constraint, at least up to Hibernate Tools 2.1.3