java - 如何加入符合条件的实体？

Question

我有两个实体类，它们的映射中不包含任何关联。

@Entity
@Table(schema = "mailing", name = "recipient_code_statistics")
public class RecipientCodeStatistics {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private int id;

    @Column(name = "recipient_code_id", unique = true)
    private long recipientCodeId;

    //GET, SET
}

和

@Entity
@Table(schema = "mailing", name = "recipient_code")
public class RecipientCode {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    private long id;

    @Column(name = "code")
    private String code;

    //GET ,SET
}

是否可以编写类似于以下内容的criteria查询:

SELECT * 
FROM recipient_code_statistic 
LEFT OUTER JOIN recipient_code
ON recipient_code_statistic.recipient_code_id = recipient_code.id
WHERE recipient_code.code = '123'

没有在映射中显式声明与 @OneToMany 注释的关联吗？

Answer 1

如果不映射两个实体对象，就不可能编写显式联接。但你可以做一个子查询。

Here is a reference to a similiar question.

And here the link to the answer containing a subquery example