java - 无法在 Hibernate 中检索自动生成的 key

Question

我创建了一个如下所示的简单表格。

CREATE TABLE CUSTOMERS
(
    CUST_ID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1, INCREMENT BY 1),
    CUSTOMER_NAME VARCHAR(24) NOT NULL,
    REGION VARCHAR(26),
    PRIMARY KEY (CUST_ID)
);

然后我用这个映射文件为这个表创建了一个映射

<class name="Customer" table="CUSTOMERS">
    <id  type="int" column="CUST_ID" >
        <generator class="native"></generator>
    </id>
    <property name="customerName" type="string" column="CUSTOMER_NAME" />
    <property name="region" type="string" column="REGION"/>
</class>

然后我创建了一个如下所示的简单类来访问数据库。

public class CustomerDao {

    public void addCustomer(Customer customer) {
        Session session = SessionManager.getSessionFactory()
                .getCurrentSession();
        session.beginTransaction();
        session.saveOrUpdate(customer);
        session.getTransaction().commit();
    }

    public List<Customer> getAllCustomer() {
        Session session = SessionManager.getSessionFactory()
                .getCurrentSession();
        session.beginTransaction();
        List<Customer> booksList = session.createQuery("from Customer").list();
        session.getTransaction().commit();
        return booksList;
    }
}

Customer 类只是一个 POJO

public class Customer {
    private int customerID;
    private String customerName;
    private String region;
    //getters setters
}

但它不绑定(bind)到表中生成的键。

public class Starter {
    public static void main(String[] args) {
        List<Customer> lstCust = daoCust.getAllCustomer();
        for (Customer cust : lstCust) {
            System.out.println(cust);
        }
    }
}

输出是这样的？

Customer Details:
------------
Customer ID:0
Customer Name: Symera
Region:Asia

Customer Details:
------------
Customer ID:0
Customer Name: Indra
Region:US

Customer Details:
------------
Customer ID:0
Customer Name:Istaf
Region:US

我是否遗漏了我的映射中的某些内容？添加客户没有问题，但检索自动生成的 key 有问题。

Answer 1

我认为您的 hbm 文件中缺少 id 标签的名称属性可能是问题所在:

<id  type="int" column="CUST_ID" name="customerID">
        <generator class="native"></generator>
    </id>