Question

我的类似乎被正确映射（如果我尝试持久化它在数据库中创建表的对象（如果它丢失了））并且我可以成功查询，但是我无法将新创建的实例保持为DB。

我在控制台中显示了SQL查询，并且它没有生成插入查询，但它之后尝试选择（最大）id

有人可以帮我找出原因吗？

SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
        Session session = sessionFactory.openSession();
        User myUser = new User();
        myUser.setUserId("Acccc");
        myUser.setPassword("abc");
        session.save(myUser);

和班级：

@Entity
@Table(name = "users")
@SuppressWarnings("serial")
public class User implements Serializable
{
    //Properties
    @Id
    @Column
    private int id;
    @Column
    private String userId;
    @Column
    private String password;

    //Getters
    public int getId() { return id; }
    public String getUserId() { return userId; }
    public String getPassword() { return password; }

    //Setters
    public void setId(int id) { this.id = id; }
    public void setUserId(String userId) { this.userId = userId; }
    public void setPassword(String password) { this.password = password; }
}

和config：

<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="nz.co.genesis.healthsafety.stripes.model.User" table="users">
    <id name="id" type="int" column="id" >
    </id>
    <property name="userId" type="java.lang.String" column="userId" not-null="false" length="45" />
    <property name="password" type="java.lang.String" column="password" not-null="false" length="45" />
</class>
</hibernate-mapping>

和DB：

id : PK NN AI
userId varchar45, default NULL
password varchar45, default: null

Answer 1

这是我的测试hibernate模型的代码

public static void main(String[] args) {
    Properties props = new Properties();
    props.setProperty("hibernate.dialect", "org.hibernate.dialect.SQLServerDialect");
    props.setProperty("hibernate.connection.driver_class", "com.microsoft.jdbc.sqlserver.SQLServerDriver");
    props.setProperty("hibernate.connection.url", "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=databaseName");
    props.setProperty("hibernate.connection.username", "username");
    props.setProperty("hibernate.connection.password", "password");

    props.setProperty("hibernate.show_sql", "true");
    props.setProperty("hibernate.transaction.flush_before_completion", "true");
    props.setProperty("hibernate.connection.release_mode", "auto");
    props.setProperty("hibernate.transaction.auto_close_session", "true");
    Configuration cfg = new Configuration();
    cfg.setProperties(props);

    // add dependency table class
    cfg.addClass(ComputerModel.class);
    cfg.addClass(CpuModel.class);       
    cfg.addClass(CdRomModel.class);
    cfg.addClass(BrandModel.class);

    SessionFactory sessions = cfg.buildSessionFactory();
    Session ss = sessions.openSession();
    List<ComputerModel> list = (ss.createQuery("from ComputerModel ")).list();

    System.out.println("Found : " + list.size() + " items.");
    System.out.println("======================================");
    for (int i = 0; i < list.size(); i++) {
        ComputerModel result = (ComputerModel) list.get(i);
        System.out.println("computerSerialNo: " + result.getComputerSerialNo() + 
                           ", " + result.getCpuModel());
    }

    ss.close();
    sessions.close();
}

Answer 2

我认为你没有配置Transaction Hibernate

Hibernate实体不是持久化的，但可以创建表和查询

2 个答案: