jpa级联保存

@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
    }
}

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