2小时学会Spring Boot学习 - 数据库操作

Posted 2020-10-31 zhcnblog

Spring-Data-JPA 整合的是Hibernate

JPA(Java Persistence API)定义了一系列对象持久化的标准,目前实现这一规范的产品有Hibernate TopLink等

mysql启动命令  mysql.server start

1.添加依赖 pom.xml

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

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
</dependency>

2.修改配置 application.yml

datasource:
  driver-class-name: com.mysql.jdbc.Driver
  url: jdbc:mysql://127.0.0.1:3306/dbgirl
  username: root
  password: after
jpa:
  hibernate:
    ddl-auto: update　　//create 会重新创建
  show-sql: true

3.新建对象类,将自动对应生成数据库中属性字段 
Girl.java

@Entity  //添加此注解
public class Girl {
    @Id //id
    @GeneratedValue //自增
    private Integer id;
    private  String cupSize;
    private  Integer age;

    public Girl() {
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getCupSize() {
        return cupSize;
    }

    public void setCupSize(String cupSize) {
        this.cupSize = cupSize;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }
}

4.新建接口文件 
GirlReposistory.java

public interface GirlReposistory extends JpaRepository<Girl,Integer> {
    //通过年龄查询
    public List<Girl> findByAge(Integer age); //此接口为扩展接口,  注意命名规则 findBy[xxx]
}

5.新建controller类 并完成注解

@RestController
@RequestMapping(value = "/girls")
public class GirlController {

    @Autowired
    private GirlReposistory girlReposistory;

    //获取女生列表
    @GetMapping(value = "/list")
    public List<Girl> girlList(){
        return girlReposistory.findAll();
    }

    //添加一个女生
    @PostMapping(value = "/add")
    public Girl girlAdd(@RequestParam(value = "cupSize") String cupSize,
                          @RequestParam(value = "age") Integer age){
        Girl girl = new Girl();
        girl.setCupSize(cupSize);
        girl.setAge(age);

        return girlReposistory.save(girl);
    }

    //通过id查询一个女生
    @GetMapping(value = "/search/{id}")
    public Girl girlSearch(@PathVariable("id") Integer id){
        return girlReposistory.findById(id).get();
    }

    //更新
    @PutMapping(value = "/update/{id}")
    public Girl girlUpdate(@PathVariable("id") Integer id,
                           @RequestParam("cupSize") String cupSize,
                           @RequestParam("age") Integer age){
        Girl girl = new Girl();
        girl.setId(id);
        girl.setCupSize(cupSize);
        girl.setAge(age);

        return girlReposistory.save(girl);
    }

    //删除
    @DeleteMapping(value = "/delete/{id}")
    public void girlDelete(@PathVariable("id") Integer id){
         girlReposistory.deleteById(id);
    }

    //通过年龄查询女生列表
    @GetMapping(value = "/age/{age}")
    public List<Girl> girlListByAge(@PathVariable("age") Integer age){
        return  girlReposistory.findByAge(age);
    }

}