外部キー休止状態の注釈

Question

この単純な外部キー制約の作業を管理することはできません。

@Entity 
@Table(name = "wheel") 
@Data 
public class WheelEntity { 
    @Id 
    @Column(name = "id") 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Integer id; 
    ... 

@Entity 
@Table(name = "bike") 
@Data 
public class BikeEntity { 
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Integer id; 

    @ManyToOne(targetEntity = WheelEntity.class, fetch=FetchType.EAGER, cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE}) 
    @JoinColumn(name = "wheel_1_id", referencedColumnName = "id") 
    @NotNull 
    private Integer wheel_1_id; 

    @ManyToOne(targetEntity = WheelEntity.class, fetch=FetchType.EAGER, cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE}) 
    @JoinColumn(name = "wheel_2_id", referencedColumnName = "id") 
    @NotNull 
    private Integer wheel_2_id; 
    ... 

私は新しいバイクを挿入したい場合は、ここでBikeEntityを永続化するとき私が得るエラーは次のとおりです。

Caused by: java.lang.IllegalArgumentException: Can not set java.lang.Integer field com.xxx.xxx.xxx.storage.WheelEntity.id to java.lang.Integer 
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167) 
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171) 
    at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java:58) 
    at sun.reflect.UnsafeObjectFieldAccessorImpl.get(UnsafeObjectFieldAccessorImpl.java:36) 
    at java.lang.reflect.Field.get(Field.java:393) 
    at org.hibernate.property.access.spi.GetterFieldImpl.get(GetterFieldImpl.java:39) 

はjava.lang.Integerのにはjava.lang.Integerを設定することはできません。 mmmmmm？奇妙な！あなたはEntity2内部Entity1の参照を持つことで関係を作成休止に役立つ

Answer 1

ため

感謝します。正しい方法は次のとおりです。

@Entity 
@Table(name = "wheel") 
@Data 
public class WheelEntity { 
    @Id 
    @Column(name = "id") 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Integer id; 
    ... 

@Entity 
@Table(name = "bike") 
@Data 
public class BikeEntity { 
    @Id 
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private Integer id; 

    @ManyToOne(targetEntity = WheelEntity.class, fetch=FetchType.EAGER, cascade={CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE}) 
    @JoinColumn(name = "wheel_1_id", referencedColumnName = "id") 
    @NotNull 
    private WheelEntity wheelEntity;