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[英]Hibernate, Spring. Multiple representations of the same entity are being merged
[英]Multiple representations of the same entity are being merged (Hibernate)
我的數據庫中有兩個表-Restaurant和RestaurantTable。 它們之間有一個@OneToMany關系(一家餐館可以有很多桌子)。 我正在嘗試向我的餐廳添加一張桌子。 我可以添加第一個表,但是一旦我嘗試添加另一個表,就會出現以下錯誤:
HTTP Status 500 - Request processing failed; nested exception is java.lang.IllegalStateException: Multiple representations of the same entity [RestaurantTable#6] are being merged. Detached: [Table number 6]; Detached: [Table number 5]
這是我的數據庫的樣子:
DROP TABLE IF EXISTS `restaurant`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `restaurant` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`restaurant_name` TEXT,
`address` TEXT,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
/*!40101 SET character_set_client = @saved_cs_client */;
DROP TABLE IF EXISTS `restaurant_table`;
/*!40101 SET @saved_cs_client = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `restaurant_table` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`table_size` int,
`table_number` int,
`restaurant_id` int(11),
PRIMARY KEY (`id`),
FOREIGN KEY (`restaurant_id`) references `restaurant`(`id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;
/*!40101 SET character_set_client = @saved_cs_client */;
我的Restaurant.java文件:
@Entity
@Table(name="restaurant")
public class Restaurant {
@Id
@Column(name="id")
@GeneratedValue(strategy= GenerationType.IDENTITY)
private Long id;
@Column(name="restaurant_name")
private String restaurantName;
@Column(name="address")
private String address;
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinColumn(name="restaurant_id")
private List<RestaurantTable> table = new ArrayList<RestaurantTable>();
// Getters and setters
RestaurantTable.java:
@Entity
@Table(name="restaurant_table")
public class RestaurantTable {
@Id
@Column(name="id")
@GeneratedValue(strategy= GenerationType.IDENTITY)
private Long id;
@Column(name="table_size")
private int tableSize;
@Column(name="table_number")
private int tableNumber;
@ManyToOne
@JoinColumn(name="restaurant_id")
private Restaurant restaurant;
// Getters and setters
我的RestaurantTableController.java:
@Controller
public class RestaurantTableController {
@Autowired
private RestaurantService restaurantService;
@Autowired
private RestaurantTableService restaurantTableService;
@RequestMapping(value="restaurant/table/{id}", method = RequestMethod.GET)
public String addRestaurantTable(Model model, @PathVariable Long id) {
model.addAttribute("table", new RestaurantTable());
return "newTable";
}
@RequestMapping(value = "restaurant/table/{id}", method = RequestMethod.POST)
public String addRestaurantTable(@PathVariable Long id, @ModelAttribute ("table") RestaurantTable table) {
Restaurant restaurant = restaurantService.getRestaurant(id);
table.setRestaurant(restaurant);
restaurant.getTable().add(table);
restaurantService.updateRestaurant(restaurant);
return "redirect:/bookings";
}
}
還有我在RestaurantDaoImpl.java中的updateRestaurant()方法:
@Override
public void updateRestaurant(Restaurant restaurant) {
Session session = this.sessionFactory.getCurrentSession();
session.merge(restaurant);
logger.info("Restaurant record updated successfully, Restaurant Details=" + restaurant);
}
任何幫助表示贊賞!
編輯:我使用的Hibernate版本是4.3.6。
另外,將我的餐廳表聲明更改為:
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER , mappedBy = "restaurant")
private List<RestaurantTable> table = new ArrayList<RestaurantTable>();
它給了我和以前一樣的錯誤。
編輯:我讀到的一種解決方案是將Cascade.ALL更改為不包括MERGE,因此代碼如下所示:
@OneToMany(cascade = {CascadeType.PERSIST, CascadeType.REMOVE, CascadeType.DETACH, CascadeType.REFRESH}, fetch = FetchType.EAGER , mappedBy = "restaurant")
private List<RestaurantTable> table = new ArrayList<RestaurantTable>();
它沒有給我一個錯誤,但是它什么也沒做,什么都沒有改變。
您的餐廳-> RestaurantTable關系正在雙方管理。 關系的只有一方可以是關系的所有者。 在這種情況下,RestaurantTable應該是關系的所有者,因為其表將具有指向另一個表的外鍵。
您需要更改Restaurant table屬性以指示該關系由RestaurantTable restaurant屬性管理。 JPA現在將使用該屬性進行持久化。
將屬性聲明更改為
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER , mappedBy = "restaurant")
private List<RestaurantTable> table = new ArrayList<RestaurantTable>();
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