我正在測試，這將檢查對象是否已保存到數據庫中。測試將保存具有唯一值的對象，然后我想從數據庫中獲取這個對象并檢查它是否不為空。Id 是自動生成的，所以我需要按名稱找到這個對象。我的測試是這樣的：@Testpublic void shouldAddNewEmployee(){    String firstNameTest = "Jon";    String lastNameTest = "Doe";    double salary1test = 10.0;    String salary2test = "10.00";    String localityTest = "LosAngeles";    String zipCodeTest = "00-000";    String streetTest = "LosAngeles str.";    int streetNumberTest = 10;    Employee testEmployee = new Employee(            firstNameTest,            lastNameTest,            salary1test,            salary2test,            localityTest,            zipCodeTest,            streetTest,            streetNumberTest);    EmployeeRepository.addNewEmployeeFromCLI(testEmployee);    String customQueryFindJonDoe = "select e from Employee e where e.firstName = Jon and e.lastName = Doe";    EntityManager entityManager = JPAUtils.openEntityManager();    List<Employee> foundJonDoe = entityManager.createQuery(customQueryFindJonDoe).getResultList();    Assertions.assertNotEquals(null, foundJonDoe);    if (entityManager.isOpen()) {        entityManager.close();    }} 運行后我得到錯誤：引起：com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException：'where 子句'中的未知列'Jon'這個查詢應該是什么樣子的？