符合所有子集合的休眠条件 [英] Hibernate Criteria to match against all child collection

问题描述

我在Product和Tag之间有一个休眠的多对多关系
产品类别具有标签"集合，可按多对多映射进行设置
我正在尝试获取与所有标签(而不是任何标签)匹配的产品
以下将获取与任何标签匹配的所有产品.

I have a hibernate many to many relationship between Product and Tag
Product class has a 'tags' collection Set as per many to many mapping
I am trying to fetch the products which matches all the tags (not any of the tags)
the following will fetch all products which matches any of the tag.

Criteria crit = session.createCriteria(Product.class,"Prdct");  
   crit.createAlias("Prdct.tags","PT");  
crit.add(Restrictions.in("PT.Name",selectedTags));  
crit.list();  

如何使用条件执行此操作?

how to do this using criteria?

推荐答案

仅对集合有用

// get the count of tags matching the criteria
DetachedCriteria subquery = DetachedCriteria.For(Product.class)
    .add(Expression.eq("id","product.id"))
    .createAlias("tags","tag")  
    .add(Restrictions.in("tag.Name", selectedTags))
    .setProjection(Projections.count("PT.Name"));

// get the Products where there all tags match
Criteria crit = session.createCriteria(Product.class,"product")
    .add(Subqueries.eq(selectedTags.getCount(), subquery);

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