CriteriaBuilder.and＆CriteriaBuilder.or，how-to？

Question

我試圖更改以下HQL使用JPA標準：

select distinct d from Department d 
left join fetch d.children c 
where d.parent is null 
and (
    d.name like :term 
    or c.name like :term 
    ) 
order by d.name 

Department有孩子的Set<Department>。

標準：

CriteriaBuilder cb = getEntityManager().getCriteriaBuilder(); 
CriteriaQuery<Department> c = cb.createQuery(Department.class); 
Root<Department> root = c.from(Department.class); 
root.fetch("children", JoinType.LEFT); 
Path<Department> children = root.join("children", JoinType.LEFT); 
c.orderBy(cb.asc(root.get("name"))); 
c.distinct(true); 
c.where(cb.isNull(root.get("parent"))); 
String param = "%" + "term" + "%"; 
cb.and(cb.like(root.<String> get("name"), param)); 
cb.or(cb.like(children.<String> get("name"), param)); 

TypedQuery<Department> tq = getEntityManager().createQuery(c); 
departments = tq.getResultList(); 

我知道這可能是一個有點簡潔，然而，HQL返回24和標準版本28.我想我不會處理：

and (x = y OR z = y) 

正確。任何指針將不勝感激。 謝謝。

Answer 1

這是你的JPQL查詢的WHERE子句：

where d.parent is null 
and (
    d.name like :term 
    or c.name like :term 
    ) 

where子句包含兩個謂詞：

d.parent is null 

和

(d.name like :term 
or c.name like :term) 

第二個謂詞是包含兩個一個or謂詞：

d.name like :term 

和

c.name like :term 

所以，你需要同樣的結構，你的條件查詢：

Predicate orClause = 
    cb.or(cb.like(root.<String>get("name"), param), 
      cb.like(children.<String>get("name"), param)); 

c.where(cb.isNull(root.get("parent")), 
     orClause);