我以为我理解了hibernate的抓取策略,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();
查询返回了数千个实体......好吧,好吧,但是在查询之后hibernate查询了其他数千个查询:
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关系是急切获取的。我不想让它变得懒惰,所以我想要一个批量提取策略。
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;
那么我该怎样做才能在批处理中获取关系?