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我有一个父表和子表之间的关系，其中，父表具有单个主键并且子表具有复合主键。但是，只有一个子表中的列被引用到父表中。Hibernate ManyToOne和列表问题
我的Hibernate类布线了这样：
父表
@Entity
@Table(name = "snippet")
public class SnippetEntity implements Serializable{
private static final long serialVersionUID = -3220451853395334879L;
@Id
@Column(name = "snpt_id", nullable=false, updatable=false)
@JsonBackReference
private String snippetId;
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "cretn_ts")
private Date creationTimeStamp;
@Column(name = "cretn_user_id")
private String creationUserId;
public String getSnippetId() {
return snippetId;
}
public void setSnippetId(String snippetId) {
this.snippetId = snippetId;
}
public Date getCreationTimeStamp() {
return creationTimeStamp;
}
public void setCreationTimeStamp(Date creationTimeStamp) {
this.creationTimeStamp = creationTimeStamp;
}
public String getCreationUserId() {
return creationUserId;
}
public void setCreationUserId(String creationUserId) {
this.creationUserId = creationUserId;
}
@Override
public String toString() {
return "SnippetEntity{" +
"snippetId='" + snippetId + '\'' +
'}';
}
}
子表
@Entity
@Table(name = "snippet_detail")
public class SnippetDetailEntity implements Serializable {
private static final long serialVersionUID = -7470223455753164243L;
@Id
@Column(name = "lang_cd", nullable=false, updatable=false)
private String language;
@Column(name = "snpt_type_cd")
private String snippetType;
@Column(name = "snpt_desc")
private String snippetDescription;
@Column(name = "snpt_txt")
private String snippetText;
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "cretn_ts")
private Date creationTimeStamp;
@Column(name = "cretn_user_id")
private String creationUserId;
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "updt_ts")
private Date updatedTimeStamp;
@Column(name = "updt_user_id")
private String updatedUserId;
@ManyToOne
@JoinColumn(name="snpt_id")
@JsonManagedReference
private SnippetEntity snippetEntity;
public SnippetDetailEntity() {}
public String getLanguage() {
return language;
}
public void setLanguage(String language) {
this.language = language;
}
public String getSnippetType() {
return snippetType;
}
public void setSnippetType(String snippetType) {
this.snippetType = snippetType;
}
public String getSnippetDescription() {
return snippetDescription;
}
public void setSnippetDescription(String snippetDescription) {
this.snippetDescription = snippetDescription;
}
public String getSnippetText() {
return snippetText;
}
public void setSnippetText(String snippetText) {
this.snippetText = snippetText;
}
public Date getCreationTimeStamp() {
return creationTimeStamp;
}
public void setCreationTimeStamp(Date creationTimeStamp) {
this.creationTimeStamp = creationTimeStamp;
}
public String getCreationUserId() {
return creationUserId;
}
public void setCreationUserId(String creationUserId) {
this.creationUserId = creationUserId;
}
public Date getUpdatedTimeStamp() {
return updatedTimeStamp;
}
public void setUpdatedTimeStamp(Date updatedTimeStamp) {
this.updatedTimeStamp = updatedTimeStamp;
}
public String getUpdatedUserId() {
return updatedUserId;
}
public void setUpdatedUserId(String updatedUserId) {
this.updatedUserId = updatedUserId;
}
public SnippetEntity getSnippetEntity() { return snippetEntity; }
public void setSnippetEntity(SnippetEntity snippetEntity) { this.snippetEntity = snippetEntity; }
@Override
public String toString() {
return "SnippetDetailEntity{" +
"language='" + language + '\'' +
", snippetType='" + snippetType + '\'' +
", snippetDescription='" + snippetDescription + '\'' +
", snippetText='" + snippetText + '\'' +
", creationTimeStamp=" + creationTimeStamp +
", creationUserId='" + creationUserId + '\'' +
", updatedTimeStamp=" + updatedTimeStamp +
", updatedUserId='" + updatedUserId + '\'' +
", snippetEntity=" + snippetEntity +
'}';
}
}
的调用来获取所有snippet_detail是：
List<SnippetDetailEntity> snippetEntities = dbService.getAll(SnippetDetailEntity.class);
public <T> List<T> getAll(Class<T> clazz) {
return getSession().createCriteria(clazz).list();
}
有378个记录snippet_detail。所以，我的问题是，当我做一个列表以获取snippet_detail中的所有行时，我会从snippet_detail获得两个唯一记录（前两个匹配此表上的主键），并且这些记录被重复多次。记录总数仍为378，但这378条记录是由多次复制的两条记录组成的。我完全困惑，我承认这可能是由于我对hibernate的理解，为什么会发生这种情况？我已经阅读了很多帖子，他们都谈论了做一个outer join休眠。我正在做什么错？如果是这样，我该如何解决这个问题？
UPDATE：
通过一些博客和文章中，我意识到，我在我的snippet_detail和方式的组合键来处理与冬眠它使用@Embeddable注释阅读。我创建了@Embeddable类，它具有snpt_id和lang_cd。我修改了我的snippet_detail实体类以使用@Embeddable类。我也感动了@ManyToOne加入到@Embeddable类，因为我想这是我需要指定连接条件（即间snippet_detail的snpt_id和snippet表的snpt_id。
现在，取精品工程，但是当我插入到snippet_detail时，我得到一个hibernate错误，说它无法执行插入操作，因为我违反了参照键约束。在我原始文章中的类中，@ManyToOne位于子类中，在这种情况下，如果该记录不存在于代码片段表中，那么对子表的插入将在父代码片段表中插入一条记录。
我的父表类与上面相同。新@Embeddable类和我的子类被修改为：
@Embeddable
public class SnippetDetailPrimaryEntity implements Serializable {
@ManyToOne
@JoinColumn(name = "snpt_id")
private SnippetEntity snippetEntity;
@Column(name = "lang_cd")
private String language;
}
@Entity
@Table(name = "snippet_detail")
public class SnippetDetailEntity implements Serializable {
@EmbeddedId
private SnippetDetailPrimaryEntity snippetDetailPrimaryEntity;
@Column(name = "snpt_type_cd")
private String snippetType;
@Column(name = "snpt_desc")
private String snippetDescription;
@Column(name = "snpt_txt")
private String snippetText;
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "cretn_ts")
private Date creationTimeStamp;
@Column(name = "cretn_user_id")
private String creationUserId;
@Temporal(TemporalType.TIMESTAMP)
@Column(name = "updt_ts")
private Date updatedTimeStamp;
@Column(name = "updt_user_id")
private String updatedUserId;
}
你的孩子谈论两个ID表！只有一个我能看到？ –
@AtimeneNazim'snpt_id'和'lang_cd'是我的子表的主键。 –
由于父对象上的manytoone映射关系，我没有在我的子类hibernate类中定义snpt_id。 –