JPA 查询本地查询结果类示例.pdfVIP

JPA 查询本地查询结果类⽰例 JPA教程 - JPA查询本地查询结果类⽰例 以下代码显⽰如何创建本机命名查询。 @Entity @Table(name = EMP) @NamedNativeQuery(name = nativeSQL, query = SELECT emp .emp_id, + emp .dept_id, emp .address_id + FROM EMP emp , EMP emp2 + WHERE ((emp2.EMP_ID = ?) AND (emp2.EMP_ID = emp .MANAGER_ID public class Professor { 例⼦ 下⾯的代码来⾃PersonDaoImpl .j ava 。 package mon; import java.util.List; import javax .persistence.EntityManager; import javax .persistence.PersistenceContext; import org.springframework.transaction.annotation.Transactional; @Transactional public class PersonDaoImpl { public void test() { prepareData(); Object l = em.createNamedQuery(findSalary).getSingleResult() printResult(l); } private void prepareData() { Address address = new Address(); address.setState(BC); Professor p = new Professor(); p.setId(0); p.setName(TOM); p.setSalary( L); p.setAddress(address); Department d = new Department(); d.setId( ); d.setName(Design); p.setDepartment(d); d.getProfessors().add(p); Phone phone = new Phone(); phone.setId( ); phone.setNumber( - - ); phone.setProfessor(p); em.persist(p); em.persist(phone); em.persist(address); em.persist(d); } private static void printResult(Object result) { if (result == null) { System.out.print(NULL); } else if (result instanceof Object[]) { Object[] row = (Object[]) result; System.out.print([); for (int i = 0; i row .length; i++) { printResult(row[i]); } System.out.print(]); } else if (result instanceof Long || result instanceof Double || result instanceof String) { System.out.print(result.getClass().getName() + : + result } else { System.out.print(result); } System.out.println(); } @PersistenceContext private EntityManager em; }