如何使用hibernate标准连接多个表,其中实体关系不是直接的? [英] How to join Multiple tables using hibernate criteria where entity relationship is not direct?
本文介绍了如何使用hibernate标准连接多个表,其中实体关系不是直接的?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有三个实体。这些是:
I have three entities. those are:
@Entity
public class Organization {
@Id
private long id;
@Column
private String name;
}
@Entity
public class Book {
@Id
private Long id;
@Column
private String name;
@ManyToOne
private Organization organization;
}
@Entity
public class Account {
@Id
private Long id;
@Column
private String name;
@ManyToOne
private Book book;
}
在这三个实体中,我想执行以下sql:
In these three entities I would like to perform following sql:
SELECT acc.name, acc.id
FROM account acc
JOIN book b on acc.book_id = b.id
JOIN organization org on b.organization_id = org.id
WHERE org.name = 'XYZ'
在这种情况下,帐户
实体与组织
无关实体直接。 帐户
实体通过预订
具有关系。如何使用hibernate条件动态查询来实现这一点?
In this case Account
entity has no relation with the Organization
entity directly. Account
entity has the relation via Book
. How can I achieve this using hibernate criteria dynamic query?
推荐答案
你可以这样做:
Criteria accountCriteria = getCurrentSession().createCriteria(Account.class,"acc");
Criteria bookCriteria = accountCriteria .createCriteria("book","b");
Criteria orgCriteria = bookCriteria.createCriteria("organization","org");
orgCriteria.add(Restrictions.eq("name", "XYZ"));
ProjectionList properties = Projections.projectionList();
properties.add(Projections.property("name"));
properties.add(Projections.property("id"));
accountCriteria.setProjection(properties);
accountCriteria.list();
这篇关于如何使用hibernate标准连接多个表,其中实体关系不是直接的?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文