Spring Boot 数据库操作及其增删改查

项目结构如下图：

在application.yml配置文件中加入以下内容：

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://192.167.0.115:3306/showtime?characterEncoding=utf-8
    username: root
    password: root
  jpa:
    hibernate:
      ddl-auto: create # 每次运行项目，都删除原有的表，创建一个新的表
    show-sql: true

运行main方法，启动项目：

@SpringBootApplication
public class ShowtimeApplication {

    public static void main(String[] args) {
        SpringApplication.run(ShowtimeApplication.class, args);
    }
}

此时查看数据库如图：

接着创建一个实体类

@Entity
public class Showtime {

    @Id
    @GeneratedValue
    private Integer id;

    private String username;

    private String address;

    private Date date;

    public Showtime(){

    }

    public Integer getId() {
        return id;
    }

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

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }
}

再次启动项目，查看数据库：

发现已生成showtime表

ShowtimeController的内容如下：

“
@RestController
public class ShowtimeController {

@Autowired
private ShowtimeRepository showtimeRepository;

/**
 * 新增
 *
 * @param showtime
 * @return
 */
@PostMapping(value = "/showtime")
public Showtime showtimeAdd(Showtime showtime){
    showtime.setDate(new Date());
    return showtimeRepository.save(showtime);
}

/**
 * 查询所有
 *
 * @return
 */
@GetMapping(value = "/showtime")
public List showtimeList(){
    return showtimeRepository.findAll();
}

/**
 * 查询一个
 *
 * @param id
 * @return
 */
@GetMapping(value="/showtime/{id}")
public Optional showtimeFindOne(@PathVariable("id") Integer id){
    return showtimeRepository.findById(id);
}

/**
 * 根据条件查询
 *
 * @param address
 * @return
 */
@GetMapping(value="/showtime/address")
public List showtimeFindByAddress(@RequestParam("address") String address){
    return showtimeRepository.findByAddress(address);
}

/**
 * 更新
 *
 * @param id
 * @param showtime
 * @return
 */
@PutMapping(value = "/showtime/{id}")
public Showtime showtimeUpdate(@PathVariable("id") Integer id, Showtime showtime){
    showtime.setDate(new Date());
    return  showtimeRepository.save(showtime);
}

}

“`