无法将数据库状态与会话同步

Question

无法将数据库状态与会话同步org.hubinate.exception.GenericJDBCException：无法更新

我在尝试更新数据库时遇到此错误。我的数据库中没有定义唯一的密钥，但id字段已被定义为主键。

这是更新功能的代码：

public String updateAction(){
       Session session = null;
       try{
            SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
            session =sessionFactory.openSession();
            org.hibernate.Transaction tx = session.beginTransaction();
            Medicine medicine = (Medicine) session.load(Medicine.class, id);
            medicine.setBrandName(brandName);
            session.update(medicine);
            tx.commit();
       }
       catch(Exception ex){
            ex.printStackTrace();
       }
       finally{
            session.close();
       }
       return "index";
    }

hibernate.config.xml：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/medicine</property>
    <property name="hibernate.connection.username">root</property>
    <property name="hibernate.connection.password">root</property>
    <property name="hibernate.show_sql">true</property>
    <property name="hibernate.current_session_context_class">thread</property>
    <property name="hibernate.query.factory_class">org.hibernate.hql.classic.ClassicQueryTranslatorFactory</property>
    <property name="hibernate.jdbc.factory_class">org.hibernate.jdbc.NonBatchingBatcherFactory</property>
    <mapping resource="mediview/Medicine.hbm.xml"/>
  </session-factory>
</hibernate-configuration>

Medicine.java:

    public class Medicine  implements java.io.Serializable {
         private String id;
         private String brandName;
         public Medicine() {
         }
     public Medicine(String id) {
          this.id = id;
     }
     public Medicine(String id, String brandName) {
          this.id = id;
          this.brandName = brandName;
     }
     public String getId() {
          return this.id;
     }
     public void setId(String id) {
          this.id = id;
     }
     public String getBrandName() {
          return this.brandName;
     }
    public void setBrandName(String brandName) {
        this.brandName = brandName;
    }
}

Medicine.ibm.xml：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 14 Aug, 2013 8:46:46 PM by Hibernate Tools 3.2.1.GA -->
<hibernate-mapping>
    <class name="mediview.Medicine" table="medicine" catalog="medicine">
        <id name="id" type="string">
            <column name="ID" length="5" />
            <generator class="assigned" />
        </id>
        <property name="brandName" type="string">
            <column name="BrandName" length="30" />
        </property>
    </class>
</hibernate-mapping>

Answer 1

在进行更新之前刷新会话状态。

Medicine medicine = (Medicine) session.load(Medicine.class, id);
session.refresh( medicine );

http://docs.jboss.org/hibernate/orm/4.0/devguide/en-US/html_single/#d0e1718