Java 将嵌套sql查询转换为jpa/hibernate

我们使用jpa/hibernate，但是我们有一些像这样的本地查询

  SELECT cp1.id AS customerbookid
  FROM customerbook cp1
  INNER JOIN customer cu ON cu.id = cp1.customerid
  WHERE cp1.autoRenew='Y'
    AND cp1.endTime < now()
AND
  (SELECT cp2.customerid
  FROM customerbook cp2
  WHERE cp1.customerid=cp2.customerid
    AND cp2.startTime > now() 
  ) IS NULL

---

是否可以将其转换为jpa？

我猜您的实体之间的关系可能是这样的：

EntityManager em;

Query q = em.createQuery("select cp1 FROM customerbook as cp1
          where cp1.customerid in (select cu.id from customer as cu)
          and cp1.autoRenew='Y'
          and cp1.endTime < :now
          and cp1.customerid not in (
            select cp2.customerid FROM customerbook cp2 where cp2.startTime > :now
          )");

q.setParameter("now", Calendar.getInstance().getTime());
// return List<CustomerBook>

q = em.createQuery("select cp1.id FROM customerbook as cp1
          where cp1.customerid in (select cu.id from customer as cu)
          and cp1.autoRenew='Y'
          and cp1.endTime < :now
          and cp1.customerid not in (
            select cp2.customerid FROM customerbook cp2 where cp2.startTime > :now
          )");

q.setParameter("now", Calendar.getInstance().getTime());
// return List<Long>

---

100%在对象中重新考虑查询是很重要的。SQL旨在设计表、列/字段，但使用JPQL，您认为从数据库实体或POJO中获取对象是为了实现JPQL吗？是的，JPQL。我们可以将hql与jpa一起使用吗？jpa是一种API。Hibernate是JPA实现之一。HQL是特定于Hibernate的语言。您需要提供类和表之间的映射。

EntityManager em;

Query q = em.createQuery("select cp1 FROM customerbook as cp1
          where cp1.customerid in (select cu.id from customer as cu)
          and cp1.autoRenew='Y'
          and cp1.endTime < :now
          and cp1.customerid not in (
            select cp2.customerid FROM customerbook cp2 where cp2.startTime > :now
          )");

q.setParameter("now", Calendar.getInstance().getTime());
// return List<CustomerBook>

q = em.createQuery("select cp1.id FROM customerbook as cp1
          where cp1.customerid in (select cu.id from customer as cu)
          and cp1.autoRenew='Y'
          and cp1.endTime < :now
          and cp1.customerid not in (
            select cp2.customerid FROM customerbook cp2 where cp2.startTime > :now
          )");

q.setParameter("now", Calendar.getInstance().getTime());
// return List<Long>