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POHibernate: how to map two columns for one table
 

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    <p>I have a user table, that has 2 foreign keys for results (one for user result, and one for average result). There is one result table for both.</p> <p>How to map such situation in hibernate? I tried one-to-one mapping, but it don't work. In java, for easy access to results I want something like that:</p> <pre><code>public class ParticipantData { int id; DataValues pickedData; DataValues averageData; } </code></pre> <p>User table:</p> <pre><code>CREATE TABLE IF NOT EXISTS `participant_data` ( `participant_data_id` int(11) NOT NULL AUTO_INCREMENT, `picked_data_id` int(11) NOT NULL, `average_data_id` int(11) NOT NULL, PRIMARY KEY (`participant_data_id`), KEY `average_data` (`average_data_id`), KEY `picked_data` (`picked_data_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ; </code></pre> <p>average_data and picked_data points to data_values_id in results</p> <p>Result table:</p> <pre><code>CREATE TABLE IF NOT EXISTS `data_values` ( `data_values_id` int(11) NOT NULL AUTO_INCREMENT, `n1` float NOT NULL, `s1` float NOT NULL, `x1` float NOT NULL, `a` float NOT NULL, `b` float NOT NULL, PRIMARY KEY (`data_values_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=36407 ; </code></pre> <p>My hibernate mapping that don't work:</p> <p>ParticipantData:</p> <pre><code>&lt;hibernate-mapping&gt; &lt;class name="com.mep.model.ParticipantData" table="participant_data"&gt; &lt;id name="id" type="int" column="participant_data_id" &gt; &lt;generator class="increment"/&gt; &lt;/id&gt; &lt;one-to-one name="pickedData" class="com.mep.model.DataValues" cascade="all" constrained="true"/&gt; &lt;one-to-one name="averageData" class="com.mep.model.DataValues" cascade="all" constrained="true"/&gt; &lt;/class&gt; &lt;/hibernate-mapping&gt; </code></pre> <p>DataValues:</p> <pre><code>&lt;hibernate-mapping&gt; &lt;class name="com.mep.model.DataValues" table="data_values"&gt; &lt;id name="id" type="int" column="data_values_id"&gt; &lt;generator class="increment" /&gt; &lt;/id&gt; &lt;property name="n1" type="float" column="n1" /&gt; &lt;property name="s1" type="float" column="s1" /&gt; &lt;property name="x1" type="float" column="x1" /&gt; &lt;property name="a" type="float" column="a" /&gt; &lt;property name="b" type="float" column="b" /&gt; &lt;one-to-one name="participantData" class="com.mep.model.ParticipantData" cascade="all"&gt;&lt;/one-to-one&gt; &lt;/class&gt; &lt;/hibernate-mapping&gt; </code></pre> <p>I will appreciate any help :)</p>
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    1. USJavaEverywhere
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    1. COWhat does "it did not work" mean? Did you get an error message or was the generated SQL wrong?
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    2. COThe error is "Caused by: java.sql.SQLException: Field 'picked_data_id' doesn't have a default value" when trying to save to database. The id should be auto generated, so I assumed that the mapping is wrong :P
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