springboot整合springdata（jpa）

Spring Data简化xml的sql语句的书写，让代码更加简洁！

1.maven添加

        
            org.springframework.boot
            spring-boot-starter-data-jpa
        

2.yml配置

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/luckymoney?zeroDateTimeBehavior=convertToNull&serverTimezone=GMT%2b8&useSSL=true
    username: root
    password: 201314
  jpa:
    hibernate:
      ddl-auto: update
    show-sql: true

3.entity

@Data
@Entity
public class LuckyMoney {
    @Id
    @GeneratedValue
    private Integer id;
    private BigDecimal money;
    /**
     * 发送放
     */
    private String  producer;
    /**
     * 接收方
     */
    private String consumer;

}

sql

CREATE TABLE `lucky_money` (
  `id` int(11) NOT NULL,
  `consumer` varchar(255) DEFAULT NULL,
  `money` decimal(5,2) DEFAULT NULL,
  `producer` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

4.mapper需要继承JpaRepository泛型<对应的entity类，主键的类型>

public interface LuckyMoneyMapper extends JpaRepository {
}

5.controller

@Controller
@RequestMapping("/lucky")
@ResponseBody
public class LuckyMoneyController {
    @Autowired
    private LuckyMoneyMapper luckyMoneyMapper;
    /**
     * 获取LuckyMoney列表
     * @return
     */
    @GetMapping("/luckys")
    public List getLuckys(){

        return luckyMoneyMapper.findAll();
    }
    /**
     * 创建一个红包
     */
    @PostMapping("/luckys")
    public LuckyMoney cteate(@RequestParam("producer") String producer,
                              @RequestParam("money")BigDecimal money){
        LuckyMoney luckyMoney=new LuckyMoney();
        luckyMoney.setProducer(producer);
        luckyMoney.setMoney(money);
        return luckyMoneyMapper.save(luckyMoney);
    }
    /**
     * 通过id获取红包信息
     */
    @GetMapping("/luckys/{id}")
    public LuckyMoney findById(@PathVariable("id") Integer id){
        return luckyMoneyMapper.findById(id).orElse(null);
    }
    /**
     * 更新红包
     */
    @PutMapping("/luckys/{id}")
    public LuckyMoney update(@PathVariable("id") Integer id,
                             @RequestParam("consumer") String consumer){
        //查找该id的红包
        Optional optional=luckyMoneyMapper.findById(id);

        //判断是否为空
        if(optional.isPresent()){
            LuckyMoney luckyMoney=optional.get();
            luckyMoney.setId(id);
            luckyMoney.setConsumer(consumer);
            return luckyMoneyMapper.save(luckyMoney);
        }
        return null;
    }

}

postman测试