---------------------Table设定信息-----------------------
Table --- Car
carId -- number -- pk 序列号
brandId -- varchar2 - fk 汽车品牌
Table --- CarBrand
brandId -- varchar2 -- pk 品牌ID
brandName -- varchar2 品牌名称
----------------------Hbm设定信息---------------------------
Car.hbm
<id name="carId">
<generator class="sequence">s_car_id</generator>
</id>
<one-to-one name="brand" class="CarBrand.class" />
CarBrand.hbm
<id name="brandId">
<generator class="assigned"/>
</id>
<property name="brandName" type="java.lang.String" column="brandName"/>
---------------------查询所有品牌为A的车辆---------------------
Criteria c = session.createCriteria();
c.createAlias(Car.class, "car");
c.createAlias("car.brand","brand");
c.add(Restriction.eq("brand.brandId","A"));'
c.list();
执行过程中产生如下报错信息
org.hibernate.TypeMismatchException: Provided id of the wrong type for class com.lw.domiane.Car Expected: class java.lang.String , got class java.lang.Long
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:109)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:905)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:842)
at org.hibernate.impl.SessionImpl.get(SessionImpl.java:835)
at com.lw.service.imp.BaseService.findById(BaseService.java:55)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:307)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:182)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:149)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:106)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:204)
at $Proxy12.findById(Unknown Source)
at com.lw.web.action.CarAction.download()(CarAction.java:51)
以上我出现的状况,有谁能帮忙解决一下,谢谢!
看来没人能回答我的问题,研究了一下,终于解决了,这里分享给大家。
首先大家可以从我的表的设定看出来,brandId是一个外键,关联到carBrand表里面的brandId,我现在希望使用one-to-one的映射模式使得Car.class的类中能够产生一个Brand的对象;
有两种映射模式,主键关联模式以及唯一外键模式
主键关联就是我们正常情况下使用的
<one-to-one name="brand" class="CarBrand.class" />
这种情况下产生的sql的形式如下:
select * from car c, carBrand cb where c.carId = cb.brandId ;
这就是我使用上面的方式报错的原因;
唯一外键模式,hbm格式如下
<many-to-one name="brand" class="CarBrand.class" unique="true" column="brandId"/>
此模式下产生sql如下
select * from car c, carBrand cb where c.barndId = cb.brandId
将Car.hbm文件中配置修改掉就可以解决这个问题了,希望对大家有帮助。