“Repeated column in mapping for entity” where each column is only mapped once

问题

I have a hibernate mapping file ParcelServicePresetIds.hbm.xml:

<hibernate-mapping>
<class name="de.delife.sql.ParcelServicePresetIds" table="ParcelServicePresetIDs" schema="dbo" catalog="xxx">
    <id name="id" type="int">
        <column name="ID" />
        <generator class="assigned" />
    </id>
    <many-to-one name="itemsBase" class="de.sql.ItemsBase" fetch="select" property-ref="itemId">
        <column name="ItemID" />
    </many-to-one>
    <property name="itemId" column="ItemID" type="java.lang.Integer"/>
    <property name="intValue" type="java.lang.Integer">
        <column name="intValue" />
    </property>
</class>
</hibernate-mapping>

When I run my program I get an error:

Initial SessionFactory creation failed.org.hibernate.MappingException: Repeated column in mapping for entity: de.sql.ParcelServicePresetIds column: ItemID (should be mapped with insert="false" update="false")

Why?

I've another entity Others.hbm.xml:

<many-to-one name="itemsBase" class="de.sql.ItemsBase" fetch="select" property-ref="itemId">
    <column name="ItemID" unique="true" />
</many-to-one>
<property name="itemId" column="ItemID" type="java.lang.Integer"/>

In this entity it's working!!! I do not understand it! Can someone explain the difference?

回答1:

You are declaring ItemID columns twice: one time with <property /> and second time with <many-to-one /> tag.
Remove one (probably <property/> declaration)

回答2:

You probably don't need to use a propertyRef here. It could simply be:

<many-to-one name="itemsBase" class="de.sql.ItemsBase" fetch="select" column="ItemID"/>

Also, you don't require the property declaration for itemId.

To answer the second part of the question:

Whenever you give propertyRef, you need to follow it up with a property definition.
If it is a 'managed column', i.e. a foreign-key-reference for example; you ought to qualify the property definition with insert="false" update="false"
However, in most cases; you donot need a propertyRef. You can do with a simple column definition in the many-to-one section.

来源：https://stackoverflow.com/questions/19632605/repeated-column-in-mapping-for-entity-where-each-column-is-only-mapped-once

标签

java

sql-server

hibernate

hibernate-mapping