Unique combination of fields

behrangsa · **Posted:** Sun Apr 08, 2007 7:14 am

Hi,

I have two domain classes, Item and Feed, and each Feed might have many items and each item only belongs to one feed.

Here's the definition of Item:

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.behrangsa.data">

    <class name="Item" table="item">

        <id name="id" column="id">
            <generator class="native" />
        </id>

        <property name="title" length="50" not-null="true"/>
        <property name="link" length="255" not-null="true" />        

        <many-to-one
            name="feed"
            column="feed_id"
            not-null="true" />

    </class>

</hibernate-mapping>

The many-to-one relation adds a feed_id column to the item table generated for the Item class. How can I make the combination of feed_id and link unique?

Thanks in advance,
Behi

behrangsa · **Posted:** Sun Apr 08, 2007 7:29 am

Solved ;)

-Behi