当我坚持一个包含订单的清单时,数据库中的结果具有不同的顺序。如何在JPA中保持与列表顺序的多对多关系?JPA:如何在多对多关系中保存订单
@Entity
@Table(name = "house")
public final class House {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
@Basic(optional = false)
@Column(name = "name")
private String name
@ManyToMany(cascade = CascadeType.ALL)
@JoinTable(name = "house_room",
joinColumns =
@JoinColumn(name = "id_house", referencedColumnName = "id"),
inverseJoinColumns =
@JoinColumn(name = "id_room", referencedColumnName = "id"))
private List<Room> rooms;
}
房屋目标:
Room room1 = new Room();
room1.setName("Kitchen");
Room room2 = new Room();
room2.setName("Bathroom");
Room room3 = new Room();
room3.setName("Bedroom");
List<Run> runs = new ArrayList<Run>();
rooms.add(0,room2);
rooms.add(1,room1);
rooms.add(2,room3);
House cottage = new House();
cottage.setRooms(rooms);
persist(cottage); // order in database should be "room2", "room1" then "room3" but it is saved as "room1", "room2" then "room3"
数据库记录没有“订单”。 – Jens
什么是'seq'? – user902383
已更正。我的错误 – sina