Hibernate：具有多对多连接表的标准？

Consider following two relations:

考虑以下两种关系：

@Entity class Foo {
    @Id id;

    @ManyToMany
    @JoinTable(name = "ATag", 
         joinColumns = @JoinColumn(name = "foo_id"),
         inverseJoinColumns = @JoinColumn(name = "tag_id"))
    Set<Tag> tags;
}

@Entity class Tag {
    @Id Long id;
    String name;
}

There is no corresponding entity class for the join table ATag. Now, I want to get all Foo instances with Tag named 'tag1', is it possible using only Criteria?

连接表ATag没有对应的实体类。现在，我希望使用名为“tag1”的Tag获取所有Foo实例，是否可以仅使用Criteria？

A sub-query maybe helpful, however, I can't create DetachedCriteria for class ATag.class which isn't existed.

子查询可能有用，但是，我不能为不存在的类ATag.class创建DetachedCriteria。

1 个解决方案

#1

Just dealt with this exact issue. You're thinking in tables, not objects. Just reference tags.name and let Hibernate take care of the rest:

刚刚处理了这个问题。你在想的是表，而不是对象。只需引用tags.name并让Hibernate处理其余的事情：

Criteria crit = session.createCriteria(Foo.class);
crit.createAlias("tags", "tagsAlias");
crit.add(Restrictions.eq("tagsAlias.name", someValue);

If you watch the SQL Hibernate spits out, you'll see it uses the join table.

如果您看到SQL Hibernate吐出，您会看到它使用连接表。

#1