Hibernate 了解使用标准和JPQL的性能比较？那么我们在这里如何使用它呢@我已经更新了我的答案（只是添加了一个简单的例子）。要了解更多信息，请点击回答中的给定链接，感谢anserI尝试了这种方法，但我在浏览…/customers/search/findcustomer

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了解使用标准和JPQL的性能比较？那么我们在这里如何使用它呢@我已经更新了我的答案（只是添加了一个简单的例子）。要了解更多信息，请点击回答中的给定链接，感谢anserI尝试了这种方法，但我在浏览…/customers/search/findcustomers时出现404错误，该页面似乎找不到。你的网址正确吗？

public interface StudentRepository extends CrudRepository<StudentEntity, Integer>{
    @Query(value = "" 
        + "SELECT s.studentname "
        + "FROM   studententity s, "
        + "       courseentity c "
        + "WHERE  s.courseid = c.courseid "
        + "       AND s.courseid IN (SELECT c.courseid "
        + "                          FROM   courseentity c "
        + "                          WHERE  c.coursename = ?1)")
    List<String> nameByCourse(String coursename);
}

public interface StudentCustomRepository {

    void anyCustomMethod();
    Student getStudentByName(String name);
}

@Service
public class StudentCustomRepositoryServiceImpl implements StudentCustomRepository {

     @PersistenceContext
     private EntityManager em;

     @Override
     public void anyCustomMethod(){
         //here use the entityManager
     }

     @Override
     StudentEntity getStudentByName(String name){
         Criteria crit = em.unwrap(Session.class).createCriteria(StudentEntity.class);
         crit.add(Restrictions.eq("name", name));
         List<StudentEntity> students = crit.list();
         return students.get(0);
     }
 }

public interface StudentRepositoryCustom {

    List<String> nameByCourse(String coursename);

}

@Service
class StudentRepositoryImpl implements StudentRepositoryCustom {

    @PersistenceContext
    private EntityManager em;

    public List<String> nameByCourse(String coursename) {            
        CriteriaBuilder cb = em.getCriteriaBuilder();
        //Using criteria builder you can build your criteria queries.
    }

}

public interface StudentRepository extends CrudRepository<StudentEntity, Integer>, StudentRepositoryCustom {

}

  CriteriaBuilder cb = entityManager.getCriteriaBuilder();

  CriteriaQuery<Country> q = cb.createQuery(Country.class);
  Root<Country> c = q.from(Country.class);
  q.select(c);