Java 如何解决休眠错误：实体映射中的重复列？
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How to solve hibernate error: Repeated column in mapping for entity?
提问by Neuquino
HI, I have the following model:
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;
}
}
And I'm getting this error:
我收到此错误：
org.hibernate.MappingException: Repeated column in mapping for entity: model.entities.Flight column: airportId (should be mapped with insert="false" update="false")
采纳答案by Affe
It's @JoinColumn you need, not @Column.
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
等等
(and as Frotthowe mentioned, it does seem a little bit odd for Flights to be OneToOne with airports. I must confess to usually ignoring the domain and assuming the names are some pseudo nonsense to facilitate the question :) )
（正如 Frotthowe 所提到的，航班与机场是一对一的似乎确实有点奇怪。我必须承认，通常会忽略域并假设名称是一些伪废话来帮助解决问题:)）
回答by Don Roby
Your Flightclass has no id defined. It's normal for an entity to have an id, and I suspect this may be related to your problem.
您的Flight课程没有定义 id。实体有 id 是正常的，我怀疑这可能与您的问题有关。
回答by FRotthowe
@OneToOneis wrong. It would mean that each Airport only has one Flight. Use @ManyToOne. And you need to specify the column that references the from and to Airport id by @JoinColumn
@OneToOne是错的。这意味着每个机场只有一个航班。使用@ManyToOne. 并且您需要指定引用 from 和 to Airport id 的列@JoinColumn
回答by Alexey
Use @JoinColumntogether with @OneToOne
使用@JoinColumn连同@OneToOne
Also note that lazy will not work in this case.
另请注意，在这种情况下，lazy 将不起作用。
回答by radeklos
I am using this for my table instead of Airports I have Cities:
我在我的桌子上使用它而不是我有城市的机场：
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;
}
//...
}
