标题翻译
HIbernate/JPA Annotation Join ManyToOne with multiple columns but with conditional OR
问题
假设我有以下实体：
公司，用户，项目和推荐
但我想要突出显示的是项目和推荐表格。下面是实体示例。
// 项目实体
@Column(name = "id")
private String id;
@Column(name = "user_id")
private String userId;
@Column(name = "company_id", nullable = true)
private String companyId;
// 推荐实体
@Column(name = "id")
private String id;
@Column(name = "user_id")
private String userId;
@Column(name = "company_id", nullable = true)
private String companyId;
@OneToMany(fetch = FetchType.LAZY)
@NotFound(action = NotFoundAction.IGNORE)
@JoinColumns({
@JoinColumn(name = "id", referencedColumnName = "user_id", nullable = true, insertable = false, updatable = false),
@JoinColumn(name = "id", referencedColumnName = "company_id", nullable = true, insertable = false, updatable = false)
})
private List<Project> projects;
上面的表格只是示例，如果没有太多意义，抱歉。
我想在Certification表格中加入Project表格。
它们之间没有直接关联，所以我需要使用这两个列，userId和companyId，来进行连接。
然而，companyId是可空的。并且每当它为空时，我仍然希望仅通过userId连接表格。
我想要实现的大致如下：
从Recommendation rec加入Project project
在rec.user_id = project.user_id and (rec.company_id = project.company_id OR rec.company_id is null)
是否可能使用Hibernate / JPA注解来实现这一点？
我的项目最近使用的是Hibernate 5。
英文翻译
Let's say I have these Entities
Company,User,Project and Recommendation
But what I want to highlight is the Project and Recommendation table.
Below is the entity sample.
//Project entity
@Column(name = "id")
private String id;
@Column(name = "user_id")
private String userId;
@Column(name = "company_id", nullable = true)
private String companyId;
//Recommendation entity
@Column(name = "id")
private String id;
@Column(name = "user_id")
private String userId;
@Column(name = "company_id", nullable = true)
private String companyId;
@OneToMany(fetch = FetchType.LAZY)
@NotFound(action = NotFoundAction.IGNORE)
@JoinColumns({
@JoinColumn(name = "id", referencedColumnName = "user_id", nullable = true, insertable = false, updatable = false),
@JoinColumn(name = "id", referencedColumnName = "company_id", nullable = true, insertable = false, updatable = false)
})
private List<Project> projects;
Above tables are just illustration, sorry if that doesn't really make sense.
I want to join Project table inside Certification table.
They both are not directly related, so I need to join using these 2 columns, userId and companyId.
However, companyId is nullable. And whenever it is null, I still want to join the table only by userId.
What I want to achieve is probably along this line:
Select from Recommendation rec Join Project project
on rec.user_id = project.user_id and (rec.company_id = project.company_id OR rec.company_id is null)
Is it possible to use hibernate / JPA annotations to achieve this?
My project uses Hibernate 5 recently
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