jpa级联保存

傷城~ 2022-12-07 12:51 161阅读 0赞

#  #

@Data
    @Entity
    @Table(name = "BB_CLOTHES")
    public class Clothes implements Serializable{ 
    	private static final long serialVersionUID = -3018808522887346432L;
    	@Id
    	@GeneratedValue(strategy=GenerationType.IDENTITY)
    	private Long id;
    
    	@Column(length = 32)
    	private String name;
    
    	@Column(length = 32)
    	private Integer size;
    
    	@Column(length = 64)
    	private Float price;
    
    	@ManyToOne(fetch=FetchType.EAGER,optional=true,cascade=CascadeType.PERSIST)
    	@JoinColumn(name = "wardrobe_id")
    	private Wardrobe wardrobe;
    }

## 级联类型说明 ##

public enum CascadeType {  
        ALL, 		// 级联全部操作
        PERSIST, 	// 级联保存操作
        MERGE, 		// 级联合并操作： 有主键就更新，没有就新增
        REMOVE,		// 级联删除操作
        REFRESH,
        DETACH
    }

@Data
    @Entity
    @Table(name="BB_WARDROBE")
    @GenericGenerator(name = "jpa-uuid", strategy = "uuid")
    public class Wardrobe { 
    	@Id
    	@GeneratedValue(generator = "jpa-uuid")
    	@Column(length = 64)
    	private String id;
    	@Column(length = 128)
    	private String name;
    	@Column
    	private Date createTime;
    }

@RestController
    @RequestMapping("/crud")
    @Slf4j
    public class CrudController { 
    	@GetMapping("/save")
    	Object save(Clothes clothes) { 
    		log.info("【clothes】={}", clothes);
    		// 保存对象
    		clothesDao.save(clothes);
    		return clothes;
    	}
    	@GetMapping("/delete")
    	Object delete(Long id) { 
    		boolean flag = false;
    		Optional<Clothes> beDeleteObject = clothesDao.findById(id);
    		if(beDeleteObject.isPresent()) { 
    			clothesDao.delete(beDeleteObject.get());
    			flag=true;
    		}
    		return flag;
    	}
    }

## 测试保存 ##

http://localhost:9080/crud/save?name=白衬衫&wardrobe.name=5号衣橱  
打印日志

2020-09-16 10:34:22.392 INFO  o.z.j.g.controller.CrudController - 【clothes】=Clothes(id=null, name=白衬衫, size=null, price=null, wardrobe=Wardrobe(id=null, name=6号衣橱, createTime=null))
    Hibernate: insert into bb_wardrobe (create_time, name, id) values (?, ?, ?)
    Hibernate: insert into bb_clothes (name, price, size, wardrobe_id) values (?, ?, ?, ?)

数据库两张表分别插入了新的记录  
返回数据为：

{ 
        "id": 24,
        "name": "白衬衫",
        "size": null,
        "price": null,
        "wardrobe": { 
            "id": "4028ed817494bcd5017494c3513b0006",
            "name": "6号衣橱",
            "createTime": null
        }
    }

![在这里插入图片描述][20200916104456142.png_pic_center]

![在这里插入图片描述][20200916104234109.png_pic_center]

## 测试删除 ##

http://localhost:9080/crud/delete?id=24  
只删除了bb\_clothes的一条记录，因为级联的时候指定了 `CascadeType.PERSIST`

[20200916104456142.png_pic_center]: /images/20221123/f6c9e9fecac5400a9c56a749a7645957.png
[20200916104234109.png_pic_center]: /images/20221123/5354d9c0403145228d1a314f00102b76.png