这是我的 POJO，一个简单的学生类。
@Proxy(lazy = false)
@Entity(name = "Students")
public class Student implements Serializable {
private static final long serialVersionUID = -9182600037012718128L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;
@Column
private String name;
private List<Homework> homework; // <-- the problematic line
public Student(){
}
public getId(){return id;}
public setId(long id){this.id = id;}
public getName(){return name;}
public setName(String name){this.name = name;}
public getHomework(){return homework;}
public setHomework(List<Homework> homework){this.homework = homework;}
}
不幸的是，即使 homework 字段没有注释(因为我目前不想将其映射到我的数据库)，我在运行应用程序时遇到此异常:
org.hibernate.MappingException: Could not determine type for: java.util.List, at table: Students, for columns: [org.hibernate.mapping.Column(homework)]
这是我的 hibernate-config.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="dataSource" class="org.apache.tomcat.dbcp.dbcp.BasicDataSource">
<property name="username" value="root" />
<property name="password" value="root" />
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://127.0.0.1:3306/test" />
<property name="testOnBorrow" value="true" />
<property name="validationQuery" value="select 1" />
</bean>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="hibernateProperties">
<value>
hibernate.dialect=org.hibernate.dialect.MySQL5InnoDBDialect
hibernate.hbm2ddl.auto=update
hibernate.show.sql=true
</value>
</property>
<property name="annotatedClasses">
<list>
<value>com.test.entity.Student</value>
</list>
</property>
</bean>
感谢任何帮助! 谢谢!
最佳答案
您可以将非映射字段设置为transient，以使hibernate不会尝试将其与数据库映射
private transient List<Homework> homework;
或者您可以使用@javax.persistence.Transient注释来注释它
@Transient
private List<Homework> homework;
hibernate 的一个特性是，它尝试将实体类的所有字段与表的相应列进行映射。因此，对于变量homework，它会在映射表中搜索具有相同名称“homework”(不区分大小写)的相应列。
请参阅文档 here ，它说
Every non static non transient property (field or method depending on the access type) of an entity is considered persistent, unless you annotate it as @Transient. Not having an annotation for your property is equivalent to the appropriate @Basic annotation.
关于java - Hibernate org.hibernate.MappingException 用于非注释字段，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/17657469/