我正在研究数据库视图的休眠实体映射;当我对它进行条件查询时,hibernate 正在生成错误的 SQL。任何帮助找出我的映射问题的帮助将不胜感激!
我有两个试图从数据库视图中获取的映射实体;该视图没有其他列,只有每个实体的 FK。这些 FK 之一可以被视为主键,因为视图对于每个主实体都有一行。所以我的视图数据库架构如下所示:
primary(primary_id, some_other_fields)
history(history_id, primary_id, some_other_fields)
view_latest_status_history(primary_id, history_id)
请注意,使用该视图是因为我只想选择每个主节点的最新历史记录,而不是所有映射的历史记录。这是我用于视图的对象,带有实体注释:
@Entity
@org.hibernate.annotations.Entity(dynamicUpdate = true)
@Table(name = "view_latest_status_history")
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE)
public class ViewLatestStatusHistoryRow implements Serializable {
private Primary primary;
private History history;
/**
* @return Returns the history.
*/
@ManyToOne(cascade = { CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REMOVE }, fetch = FetchType.LAZY)
@JoinColumn(name = "history_id", nullable = true)
@AccessType("field")
public History getHistory() {
return history;
}
//equals() and hashCode() implementations are omitted
/**
* @return Returns the primary.
*/
@Id
@ManyToOne(cascade = { CascadeType.MERGE, CascadeType.PERSIST, CascadeType.REMOVE }, fetch = FetchType.LAZY)
@JoinColumn(name = "primary_id", nullable = false)
@AccessType("field")
public Primary getPrimary() {
return primary;
}
}
Primary 和 History 对象都具有完整的工作实体注释。
我的标准设置:
criteria.add(Restrictions.in("primary", [collection of primary objects]));
criteria.setFetchMode("primary", FetchMode.JOIN);
criteria.setFetchMode("history", FetchMode.JOIN);
以及(错误的)生成的 SQL:
select this_.primary as primary78_1_, this_.primary_id as prim2_78_1_, primary2_.history_id as unique1_56_0_, ...history fields
from DB_CATALOG.dbo.view_latest_status_history this_
left outer join DB_CATALOG.dbo.history primary2_ on this_.primary_id=primary2_.primary_id
where this_.specChange in (?, ?...)
在编辑项目数据库模式的细节时,我可能搞砸了一些事情,但关键是“选择”子句中的第一个字段是错误的:
this_.primary (view_latest_status_history.primary) 不是一个字段;该字段应称为primary_id。我认为这可能与主字段上的@Id 注释有关?任何想法如何解决这一问题?如果我删除 @Id,我会收到一条错误消息,告诉我该实体没有主键。
更新:
我不再使用连接表表示法将视图映射为字段(如下所示)。注释已修改如下。此解决方案在 HQL 中正常工作,并在启用 hbm2ddl 时生成预期的架构,但我没有使用条件查询重新测试它。
@Entity
@Table(name = "view_latest_status_history")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class ViewLatestStatusHistoryRow implements Serializable {
private String id;
private Primary primary;
private History history;
/**
* @return Returns the history.
*/
@OneToOne(optional = true)
@JoinColumn(name = "history_id", nullable = true)
@AccessType("field")
public History getHistory() {
return history;
}
//equals() and hashCode() implementations are omitted
@Id
@Column(name = "primary_id", nullable = false)
@Override
@AccessType(value = "field")
public String getId() {
return id;
}
/**
* @return Returns the primary.
*/
@PrimaryKeyJoinColumn(name = "primary_id", referencedColumnName = "unique_id")
@OneToOne(optional = false)
@AccessType("field")
public Primary getPrimary() {
return primary;
}
}