java - 如何解决休眠错误：实体映射中的重复列？

Question

嗨，我有以下型号：

@Entity
class Flight{
  private Airport airportFrom;
  private Airport airportTo;

  @OneToOne(fetch=FetchType.LAZY,optional=false)
  public Airport getAirportFrom(){
    return this.airportFrom;
  }

  @OneToOne(fetch=FetchType.LAZY,optional=false)
  public Airport getAirportTo(){
    return this.airportTo;
  }
}

@Entity
class Airport{
  private Integer airportId;

  @Id
  public Integer getAirportId(){
    this.airportId;
  }
}

我收到了这个错误：

org.hibernate.MappingException: Repeated column in mapping for entity: model.entities.Flight column: airportId (should be mapped with insert="false" update="false")

Answer 1

您需要的是@JoinColumn，而不是@Column。

  @OneToOne(fetch=FetchType.LAZY,optional=false)
  @JoinColumn(name="airportFrom", referencedColumnName="airportId")
  public Airport getAirportFrom(){
    return this.airportFrom;
  }

ETC

（正如 Frotthowe 所提到的，Flights 与机场的 OneToOne 似乎有点奇怪。我必须承认通常忽略域并假设名称是一些伪废话以促进问题:)）

Answer 2

@OneToOne是错的。这意味着每个机场只有一个航班。使用@ManyToOne. 您需要指定引用 from 和 to Airport id 的列@JoinColumn

Answer 3

您的Flight班级没有定义 id。实体有 id 是正常的，我怀疑这可能与您的问题有关。

Answer 4

@JoinColumn一起使用@OneToOne

另请注意，惰性在这种情况下不起作用。

Answer 5

我将它用于我的桌子而不是我拥有城市的机场：

class Tender implements java.io.Serializable {
  //...
  @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
  @JoinColumn(name = "city")
  public City getCity() {
    return this.city;
  }

  @OneToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
  @JoinColumn(name = "tour_city")
  public City getTourCity() {
    return this.tourCity;
  }
  //...
}

City implements java.io.Serializable {
  //...
  @Id
  @SequenceGenerator(name = "city_pkey", sequenceName = "city_uid_seq", allocationSize = 1)
  @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "city_pkey")
  @Column(name = "uid", unique = true, nullable = false)
  public int getUid() {
    return this.uid;
  }
  //...
}