翻譯HQL子查詢標準

Question

我想翻譯HQL的這種結構：

FROM Entity_1 obj 
WHERE obj IN (FROM Entity2) OR 
     obj IN (FROM Entity3) 

如何能不能做到？

Answer 1

它在休眠標準文檔解釋：http://docs.jboss.org/hibernate/core/3.3/reference/en/html/querycriteria.html#querycriteria-detachedqueries

甲的DetachedCriteria也可被用於表達子查詢。涉及子查詢的標準實例可以通過子查詢或屬性獲取。

DetachedCriteria avgWeight = DetachedCriteria.forClass(Cat.class) 
    .setProjection(Property.forName("weight").avg()); 
session.createCriteria(Cat.class) 
    .add(Property.forName("weight").gt(avgWeight)) 
    .list(); 

DetachedCriteria weights = DetachedCriteria.forClass(Cat.class) 
    .setProjection(Property.forName("weight")); 
session.createCriteria(Cat.class) 
    .add(Subqueries.geAll("weight", weights)) 
    .list(); 

相關子查詢也是可能的：

DetachedCriteria avgWeightForSex = DetachedCriteria.forClass(Cat.class, "cat2") 
    .setProjection(Property.forName("weight").avg()) 
    .add(Property.forName("cat2.sex").eqProperty("cat.sex")); 
session.createCriteria(Cat.class, "cat") 
    .add(Property.forName("weight").gt(avgWeightForSex)) 
    .list(); 

Answer 2

我非常新的HQL，但我建議像下面這樣：

DetachedCriteria sub1 = DetachedCriteria.forClass(Entitiy2); 
DetachedCriteria sub2 = DetachedCriteria.forClass(Entity3); 

Criteria criteria = getYourSession().createCriteria(Entity_1.class, "obj"); 
criteria.add(Restrictions.or(Subqueries.propertyIn("obj", sub1), Subqueries.propertyIn("obj", sub2)); 

請糾正我，如果我錯了。