1.引入jpa依赖

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

2.创建application.yml

spring:
  datasource:
    url: jdbc:mysql://localhost/bike?serverTimezone=UTC
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver
#更新自己数据表结构 控制台看到sql
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

3.创建实体类User.java

@Entity //配置JPA映射关系 和数据表映射
@Table(name = "tbl_user") //和数据库表对应，没写的话时默认类名小写
public class User  {

    @Id //标记主键
    @GeneratedValue(strategy = GenerationType.IDENTITY) //自主键
    private Integer id;

    @Column(name = "last_name",length = 50)//和数据表相对应的列
    private String lastName;
    @Column //省略的话默认就是属性名
    private String email;

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", lastName='" + lastName + '\'' +
                ", email='" + 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.创建UserJpaReposity接口

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

5.UserController.java

public class UserController {

    @Autowired
    UserResposity userResposity;

    @GetMapping("/user/{id}")
    public User getUser(@PathVariable("id") Integer id){
        User user = userResposity.getOne(id);
        return user;
    }

    @GetMapping("/user")
    public User insertUser(User user){
        User save = userResposity.save(user);
        return save;
    }
}