Hibernate:使用带有集合的标准(HashSet)

时间:2011-11-21 16:38:44

标签: java hibernate hql criteria

我有以下课程:

  public class Folder{
      private Set<Documents> documents;
      private Set<Clip> clips;
  }

  public class Clip{
      private Owner owner;
  }

我需要在所有者黄色 文件夹中找到漂亮 文档的列表文件夹中的 剪辑名称就像搜索字符串一样。像这样(不工作):

Criteria criteria = session.createCriteria(Document.class);

criteria.add(Restrictions.eq("isNice", 1));
criteria.createCriteria("folder").add(Restrictions.eq("isYellow", 1));
criteria.createCriteria("clips");
criteria.createCriteria("owner").add(Restrictions.like("name", search));

List documents = criteria.list();

如何为HashSet创建条件? 或者

  • 也许我应该使用hql查询
  • 也许我只能编辑List documents,删除错误的条目?
  • 甚至可以使用标准吗?
  • 如果不是另一种方式?

修改。我找到了这段代码:

    List cats = sess.createCriteria(Cat.class)
    .createCriteria("kittens", "kt")
        .add( Restrictions.eq("name", "F%") )
    .setResultTransformer(Criteria.ALIAS_TO_ENTITY_MAP)
    .list();
Iterator iter = cats.iterator();
while ( iter.hasNext() ) {
    Map map = (Map) iter.next();
    Cat cat = (Cat) map.get(Criteria.ROOT_ALIAS);
    Cat kitten = (Cat) map.get("kt");
}

但我无法理解它究竟是做什么的。什么结果变形金刚?

请,任何建议或提示都会有所帮助!谢谢!

1 个答案:

答案 0 :(得分:2)

Criteria criteria = session.createCriteria(Document.class, "document");
criteria.add(Restrictions.eq("document.nice", true));
criteria.createAlias("document.folder", "folder");
criteria.add(Restrictions.eq("folder.yellow", true));
criteria.add(Subqueries.exists(clipOwnerWithNameInFolder(name, "folder"));

private DetachedCriteria clipOwnerWithName(String searchedName, String aliasOfFolder) {
    DetachedCriteria c = DetachedCriteria.forClass(Clip.class, "clip");
    c.createAlias("clip.owner", "owner");
    c.createAlias("clip.folder", "clipFolder");
    c.add(Restrictions.propertyEq("clipFolder.id", aliasOfFolder + ".id");
    c.add(Restrictions.like("owner.name", searchedName);
    c.setProjection(Projections.id());
}

这需要剪辑/文件夹关联是双向的(即您需要folder中有Clip字段。如果不是这样,可以像这样创建分离的标准:

private DetachedCriteria clipOwnerWithName(String searchedName, String aliasOfFolder) {
    DetachedCriteria c = DetachedCriteria.forClass(Folder.class, "clipFolder");
    c.createAlias("clipFolder.clips", "clip");
    c.createAlias("clip.owner", "owner");
    c.add(Restrictions.propertyEq("clipFolder.id", aliasOfFolder + ".id");
    c.add(Restrictions.like("owner.name", searchedName);
    c.setProjection(Projections.property("clip.id"));
}