我以为我了解hibernate的获取策略,但似乎我错了。
所以,我有一个 namedNativeQuery:
@NamedNativeQueries({
@NamedNativeQuery(
name = "getTest",
resultClass = ArticleOnDate.class,
query = "SELECT `a`.`id` AS `article_id`, `a`.`name` AS `name`, `b`.`price` AS `price` FROM article a LEFT JOIN price b ON (a.id = b.article_id) WHERE a.date <= :date"
)
})
@Entity()
@Immutable
public class ArtikelOnDate implements Serializable {
@Id
@OneToOne
@JoinColumn(name = "article_id")
private Article article;
...
}
然后我称之为:
Query query = session.getNamedQuery("getTest").setDate("date", date);
List<ArticleOnDate> list = (List<ArticleOnDate>) query.list();
该查询返回数千个实体......好吧,好的,但在查询之后休眠查询数千个其他查询:
Hibernate:
select
article0_.id as id1_0_0_,
article0_.bereich as name2_0_0_,
price1_.price as price1_14_1_
from
article artikel0_
where
artikel0_.id=?
好的,这是逻辑,因为 @OneToOne 关系被急切地获取。我不想偷懒,所以我想要一个批量获取策略。
我试图注释 Article 属性,但它不起作用:
@Id
@OneToOne
@JoinColumn(name = "article_id")
@BatchSize(size=100)
private Article article;
那么我该怎么做才能批量获取关系呢?