Hibernate unique constraint over two column

marcello · **Posted:** Sun Jun 19, 2005 5:44 am

Hibernate version:2.0

Name and version of the database you are using:mysql

Hi ,

I want to mapping a group of 2 columns (nome,areaadmin) as unique constraint but I don' t like a composite key, my primary key is simple id type int.
One of two columns is also a foreign key(areaadmin)

here the code without this change.........
(I have got 1 columns as attribute 'unique' )
**********************+

<class name="com.mainsoft.pojo.CompetenzeAdmin"
table="COMPETENZEADMIN">

<id name="id" type="int"
column="COMPETENZEADMIN_ID">
<meta attribute="scope-set">protected</meta>

<generator class="native"/>
</id>
<property name="nome" type="string"
not-null="true" unique="true"/>

<set name="conoscenze" cascade="all"
inverse="true" lazy="true">
<key column="competenzeadmin_id"/>
<one-to-many
class="com.mainsoft.pojo.ConoscenzeAdmin"/>
</set>

<many-to-one name="areaadmin"
class="com.mainsoft.pojo.AreaAdmin"
column="areaadmin_id"/>
</class>
********************

help me!
Thanks,
Marcello.

ramnath · **Posted:** Sun Jun 19, 2005 11:57 pm

HI

I have the same problem but with Four Colomn.

A Sample will be very much appreciated

Thanks for Team

gavin · **Posted:** Mon Jun 20, 2005 12:16 am

unique-key="indexName"

Or <natural-id>

alspaughb · **Posted:** Fri Aug 11, 2006 7:12 pm

I have the same problem with Hibernate 3.1.3. I am using <id></id> to identify the surrogate key.

I can use unique-key="indexName" and not-null="true" to identify the properties that make up the natural key and everything works fine.

However, when I try to bracket the natural key properties inside <natural-id> </natural-id>, I get an exception:

Code:

Caused by: org.xml.sax.SAXParseException: The content of element type "class" must match "(meta*,subselect?,cache?,synchronize*,comment?,tuplizer*,(id|composite-id),discriminator?,natural-id?,(version|timestamp)?,(property|many-to-one|one-to-one|component|dynamic-component|properties|any|map|set|list|bag|idbag|array|primitive-array)*,((join*,subclass*)|joined-subclass*|union-subclass*),loader?,sql-insert?,sql-update?,sql-delete?,filter*,resultset*,(query|sql-query)*)".
   at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
   at org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
   at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
   at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
   at org.apache.xerces.impl.dtd.XMLDTDValidator.handleEndElement(Unknown Source)
   at org.apache.xerces.impl.dtd.XMLDTDValidator.endElement(Unknown Source)
   at org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanEndElement(Unknown Source)
   at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
   at org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
   at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
   at org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
   at org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
   at org.apache.xerces.parsers.AbstractSAXParser.parse(Unknown Source)
   at org.dom4j.io.SAXReader.read(SAXReader.java:465)
   at org.hibernate.cfg.Configuration.addInputStream(Configuration.java:422)
   ... 25 more

Any ideas?

Bruce

alspaughb · **Posted:** Sun Aug 13, 2006 4:51 pm

I found the problemon my own. The order of the tags is important. It you have to specify the id, then the natural-id, then the version. I had the id, the version, then the natural-id.

Bruce