HBM
order:
<class name="com.model.Card" table="card">
<id name="id" type="java.lang.Integer">
<column name="id" />
<generator class="foreign">
<param name="property">users</param>
</generator>
</id>
<property name="cardName" type="java.lang.String"
column="cardNum" />
<one-to-one name="users" class="com.model.Users" />
</class>
user:
<one-to-one name="card" class="com.model.Card" cascade="all" />
然后就是在user中有一个多对多的关系
<set name="userrole" table="userole" cascade="save-update"
inverse="false">
<key>
<column name="uid"></column>
</key>
<composite-element class="com.model.Roleuser">
<parent name="us" />
<many-to-one name="rol" column="oid"
class="com.model.Roles" />
</composite-element>
</set>
现在运行一对一的关系运行是没有问题的
假如把user中的一对一的关系注释了，运行多对多的关系也是没有问题的，可是把一对一的关系拿出来，就不行了，提示有错误，如下：
Exception in thread "main" org.hibernate.id.IdentifierGenerationException: attempted to assign id from null one-to-one property: users
at org.hibernate.id.ForeignGenerator.generate(ForeignGenerator.java:44)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:91)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:98)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:502)
at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:494)
at org.hibernate.engine.CascadingAction$1.cascade(CascadingAction.java:134)
at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:213)
at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:157)
at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:108)
at org.hibernate.engine.Cascade.cascade(Cascade.java:248)
at org.hibernate.event.def.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:410)
at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:299)
at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:167)
at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:101)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:186)
at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:175)
at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:530)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:518)
at org.hibernate.impl.SessionImpl.save(SessionImpl.java:514)