我正面临着如何管理特定模型的映射的问题。
这是一个多租户应用程序,我们已经选择在每个实体中包含“tenant_id”,因此我们不需要每次需要获取实体时都联合起来(事实上,这是我问题的根源) ...)。
该模型如下:
+--------------------+ +---------------+
| Book | | Author |
+--------------------+ +---------------+
| id (pk) | | id (pk) |
| tenant_id (pk)(fk) | | tenant_id (pk |
| author_id (fk) | | name |
| title | +---------------+
+--------------------+
如您所见,tenant-id位于每个实体中,并且是主键的一部分。我们使用@IdClass来管理复合键。这是代码:
@Data
public class TenantAwareKey implements Serializable {
private UUID id;
private Integer tenantId;
}
@IdClass(TenantAwareKey.class)
@Entity
@Table(name = "BOOK")
@Data
public class Book {
@Id
@GeneratedValue
@Column(name = "ID")
private UUID id;
@Id
@Column(name = "TENANT_ID")
private Integer tenantId;
private String title;
@ManyToOne
@JoinColumns(
value = {
@JoinColumn(referencedColumnName = "id", name = "author_id"),
@JoinColumn(referencedColumnName = "tenant_id", name = "tenant_id", insertable = false, updatable = false)
})
private Author author;
}
@IdClass(TenantAwareKey.class)
@Entity
@Data
public class Author {
@Id
@GeneratedValue
@Column(name = TenantAwareConstant.ENTITY_ID_COLUMN_NAME)
private UUID id;
@Id
@Column(name = TenantAwareConstant.TENANT_ID_COLUMN_NAME)
private Integer tenantId;
private String name;
}
然后,在运行我的应用程序时,我最终得到:
Caused by: org.hibernate.AnnotationException: Mixing insertable and non insertable columns in a property is not allowed:
com.pharmagest.durnal.tenant.entity.BookNoDuplicateColumn.author
at org.hibernate.cfg.Ejb3Column.checkPropertyConsistency(Ejb3Column.java:725)
at org.hibernate.cfg.AnnotationBinder.bindManyToOne(AnnotationBinder.java:3084)
(...)
如果我不尝试“共享”tenant_id列,我设法使其工作,当我只有一个具有此tenant_id的外键时可以接受,但随着外键数量的增加越来越少,导致添加每次一个tenant_id列,重复信息和破坏内存......
在挖掘了一下之后,我在Hibernate中找到了一个未解决的问题:https://hibernate.atlassian.net/browse/HHH-6221
它已经修复了多年......所以,我的问题是:你是否遇到过这样的映射,当我有一个与主键共享字段的外键时,是否有一个避免重复columen的解决方案?
如here所述,您可以通过将@JoinColumnOrFormula用于列id_tenant来绕过验证。
您应该映射作者的关联,如下所示:
@JoinColumnsOrFormulas(
value = {
@JoinColumnOrFormula(column = @JoinColumn(referencedColumnName = "id", name = "author_id")),
@JoinColumnOrFormula(formula = @JoinFormula(referencedColumnName = "tenant_id", value = "tenant_id"))
})