2017-09-15 98 views
1

随着Permission是一个枚举,是可以选择的所有用户,而无需使用JPA标准API一定的权限:标准API不@ElementCollection

@Entity 
public class User { 

    @ElementCollection 
    @CollectionTable(joinColumns = @JoinColumn(name = "USER_ID")) 
    private Set<Permission> permissions = new HashSet<>(); 

} 

我目前的做法(没有返回值):

// em => EntityManager 
// cb => CrieriaBuilder 
Root<User> root = query.from(User.class); 
query.select(root); 
SetJoin<User, Permission> join = root.joinSet("permissions"); 
query.where(cb.not(cb.equal(join, Permission.RULE_THEM_ALL))); 
List<User> result = em.createQuery(query).getResultList(); 
+0

为什么SQL标签? – jarlh

+1

JPQL等价于'SELECT u FROM User u WHERE:myPerm IN u.permissions'你不能做“Set == elementValue”,但你可以使用IN – DN1

回答

0

我最终使用子查询来选择具有特定权限的所有用户,并将它们从结果集中排除。

CriteriaQuery<User> query = cb.createQuery(User.class); 
Root<User> root = query.from(User.class); 
query.select(root); 

Subquery<Long> subquery = query.subquery(Long.class); 
Root<User> subroot = subquery.from(User.class); 
SetJoin<User, Permission> join = subroot.join("permissions"); 
subquery.select(subroot.get("id")).where(cb.equal(join, Permission.RULE_THEM_ALL)); 

query.where(root.get("id").in(subquery).not());