SpringBoot整合JPA案例

爱被打了一巴掌 2022-03-08 07:49 315阅读 0赞

### 一、编写一个实体类（bean）和数据表进行映射，并且配置好映射关系 ###

/**
     * @author hq.zheng
     * @create 2019-03-14-下午 4:28
     */
    //使用JPA注解配置映射关系
    @Entity//告诉JPA这是一个实体类(和数据表映射的类)
    @Table(name="tbl_user")//指定和哪个数据表对应；如果不填默认表名是类名小写user
    public class User {
        @Id//这是一个主键
        @GeneratedValue(strategy = GenerationType.IDENTITY)//自增主键
        private Integer id;
        @Column(name = "last_name",length = 50)//这是和数据表对应的一个列
        private String lastName;
        @Column//省略默认列名就是属性名
        private String email;
    
        public Integer getId() {
            return id;
        }
    
        public void setId(Integer id) {
            this.id = id;
        }
    
        public String getLastName() {
            return lastName;
        }
    
        public void setLastName(String lastName) {
            this.lastName = lastName;
        }
    
        public String getEmail() {
            return email;
        }
    
        public void setEmail(String email) {
            this.email = email;
        }

### 二、编写一个Dao接口来操作实体类对应的数据表（Repository） ###

/**
     * @author hq.zheng
     * @create 2019-03-14-下午 4:43
     */
    //继承JpaRepository来完成对数据库的CRUD操作
    public interface UserRepository extends JpaRepository<User,Integer> {
    }

### 三、全局配置文件中配置基本的配置JpaProperties ###

spring:
      datasource:
        url: jdbc:mysql://192.168.43.118:3307/jpa
        username: root
        password: 123456
        driver-class-name: com.mysql.jdbc.Driver
      jpa:
        hibernate:
    #      更新或创建数据表结构
          ddl-auto: update
    #   控制台显示SQL
        show-sql: true

### 四、编写controller测试接口是否整合成功 ###

/**
     * @author hq.zheng
     * @create 2019-03-14-下午 4:57
     */
    @RestController
    public class UserController {
        @Autowired
        UserRepository userRepository;
        //根据id查找
        @GetMapping("/user/{id}")
        public User getUser(@PathVariable("id") Integer id){
            User user = userRepository.findOne(id);
            return user;
        }
        //新增
        @GetMapping("/user")
        public User insertUser(User user){
            User user1 = userRepository.save(user);
            return user1;
        }
    }

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