springdata_多表关系中的一对一__小案例

一、创建maven工程，引入依赖，设置配置文件

依赖和配置文件的设置可以参考，之前的博客《springdata__jpa》

二、创建实体类

1.customer类

package cn.dzl.jpa.entity;

import javax.persistence.*;

@Entity@Table(name = "cust_customer")public class Customer {    //设置主键自增策略    @GeneratedValue(strategy = GenerationType.IDENTITY)    @Id    private long custId;    private String custName;    private String custSource;    private String  custIndustry;    private String custLevel;    private String custAddress;    private String custPhone;

    @PrimaryKeyJoinColumn//主键关联    @OneToOne(cascade = CascadeType.ALL)//设置联级关联，效果是，两个有关联的表，可以单独地改变其中一个表    private CustomerExt ext; //该字段表明关联的是哪个表对象

    public CustomerExt getExt() {        return ext;    }

    public void setExt(CustomerExt ext) {        this.ext = ext;    }

    public long getCustId() {        return custId;    }

    public void setCustId(long custId) {        this.custId = custId;    }

    public String getCustName() {        return custName;    }

    public void setCustName(String custName) {        this.custName = custName;    }

    public String getCustSource() {        return custSource;    }

    public void setCustSource(String custSource) {        this.custSource = custSource;    }

    public String getCustIndustry() {        return custIndustry;    }

    public void setCustIndustry(String custIndustry) {        this.custIndustry = custIndustry;    }

    public String getCustLevel() {        return custLevel;    }

    public void setCustLevel(String custLevel) {        this.custLevel = custLevel;    }

    public String getCustAddress() {        return custAddress;    }

    public void setCustAddress(String custAddress) {        this.custAddress = custAddress;    }

    public String getCustPhone() {        return custPhone;    }

    public void setCustPhone(String custPhone) {        this.custPhone = custPhone;    }

    @Override    public String toString() {        return "Customer{" +                "custId=" + custId +                ", custName=‘" + custName + ‘\‘‘ +                ", custSource=‘" + custSource + ‘\‘‘ +                ", custIndustry=‘" + custIndustry + ‘\‘‘ +                ", custLevel=‘" + custLevel + ‘\‘‘ +                ", custAddress=‘" + custAddress + ‘\‘‘ +                ", custPhone=‘" + custPhone + ‘\‘‘ +                ‘}‘;    }}

2.CustomerExt类

package cn.dzl.jpa.entity;

import javax.persistence.*;

@Entity@Table(name = "customer_ext")public class CustomerExt {    @Id//该注解在哪一个字段上，哪个字段就是主键    @GeneratedValue(strategy = GenerationType.IDENTITY)//设置主键为自增状态    private long extId;    private String memo;    private String info;    @PrimaryKeyJoinColumn//该注解表明两个表之间是主键关联    @OneToOne//两个表之间的关系是一对一    private Customer customer;//该字段表明，关联的是哪个表对象

    public Customer getCustomer() {        return customer;    }

    public void setCustomer(Customer customer) {        this.customer = customer;    }

    public long getExtId() {        return extId;    }

    public void setExtId(long extId) {        this.extId = extId;    }

    public String getMemo() {        return memo;    }

    public void setMemo(String memo) {        this.memo = memo;    }

    public String getInfo() {        return info;    }

    public void setInfo(String info) {        this.info = info;    }

    @Override    public String toString() {        return "CustomerExt{" +                "extId=" + extId +                ", memo=‘" + memo + ‘\‘‘ +                ", info=‘" + info + ‘\‘‘ +                ‘}‘;    }}

三、创建dao接口(一定要继承JpaRepository<实体类型，主键类型>)

1.CustomerDao

package cn.dzl.jpa.dao;

import cn.dzl.jpa.entity.Customer;import org.springframework.data.jpa.repository.JpaRepository;

public interface CustomerDao extends JpaRepository<Customer,Long> {}

2.CustomerExtDao

package cn.dzl.jpa.dao;

import cn.dzl.jpa.entity.CustomerExt;import org.springframework.data.jpa.repository.JpaRepository;

public interface CustomerExtDao extends JpaRepository<CustomerExt,Long> {}

四、测试类OneToOne

package cn.dzl;

import cn.dzl.jpa.dao.CustomerDao;import cn.dzl.jpa.dao.CustomerExtDao;import cn.dzl.jpa.entity.Customer;import cn.dzl.jpa.entity.CustomerExt;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.annotation.Commit;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import org.springframework.transaction.annotation.Transactional;

@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:applicationContext.xml")public class OneToOne {    @Autowired    CustomerDao customerDao;    @Autowired    CustomerExtDao customerExtDao;    @Test    //更改数据库，需要用到事物    @Transactional    //提交    @Commit    public void addCustomer(){        //创建customer对象        Customer customer = new Customer();        customer.setCustName("丁老大");        customer.setCustAddress("北京");        //创建customerExt对象        CustomerExt customerExt = new CustomerExt();        customerExt.setInfo("今天心情不错");        customerExt.setMemo("打球去");        //设置对象关联关系        customer.setExt(customerExt);        customerExt.setCustomer(customer);        //调用dao层方法保存到数据库中        customerDao.save(customer);//        customerExtDao.save(customerExt);    }}

原文地址：https://www.cnblogs.com/Hubert-dzl/p/11665058.html