SpringBoot系列二十：整合JPA

小咪咪 2022-10-01 10:46 215阅读 0赞

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1、引入依赖

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

2、yml配置

spring:
      datasource:
        url: jdbc:mysql://192.168.106.130:3305/jpa
        username: root
        password: 123456
        driver-class-name: com.mysql.jdbc.Driver
      jpa:
        hibernate:
          #更新或者创建数据表结构
          ddl-auto: update
        #控制台显示SQL
        show-sql: true

3、编写实体类和数据表进行映射，并且配置好映射关系

/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") //@Table来指定和哪个数据表对应;如果省略默认表名就是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;
        }
    }

4、编写Dao接口来操作实体类对应的数据表（Repository）

//继承JpaRepository来完成对数据库的操作
    public interface UserRepository extends JpaRepository<User,Integer> {
    }

测试：

@RestController
    public class UserController {
    
        @Autowired
        UserRepository userRepository;
    
        @GetMapping("/user/{id}")
        public User getUser(@PathVariable("id") Integer id){
            User user = userRepository.findOne(id);
            return user;
        }
    
        @GetMapping("/user")
        public User insertUser(User user){
            User save = userRepository.save(user);
            return save;
        }
    
    }

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