从一个表中获取数据并插入到另一个表中 JPA

Question

我是 JPA 的初学者。根据要求，我正在尝试从多个表（emp_boarding_details、amex_emp_detail、emp_offboarding_details）中获取数据并插入到另一个表中，即emp_boarding_history。

1. EmpBoardingHistoryRepository.java：

public interface EmpBoardingHistoryRepository extends JpaRepository<EmpBoardingHistory, Long> {

@Query(nativeQuery = true, value = "SELECT new com.boarding.boardinghistory.resource.EmpBoardingHistory**(ebd.exemption_type_txt, ebd.exemption_remarks_txt, ebd.emp_no_int, ebd.first_name_txt, ebd.middle_name_txt, ebd.last_name_txt, ebd.email_id_txt, ebd.emp_or_contractor_ind, ebd.vendor_laptop_desktop_asset_txt, ebd.country_origin_txt, ebd.status_txt, aed.billing_po_no_txt, aed.contractor_id_txt, aed.contract_type_txt, aed.proj_master_cd_txt, aed.amex_email_id_txt, aed.amex_laptop_desktop_asset_id_txt, aed.ads_id_txt, aed.cost_center_txt, aed.contractor_id_creation_date, aed.first_billing_date, aed.clarity_resource_role_txt, aed.platform_id_txt, aed.premium_technology_txt, aed.resource_status_txt, aed.onboard_completion_date, eod.resource_leaving_date, eod.departure_date) FROM emp_boarding_details ebd, amex_emp_details aed, emp_offboarding_details eod WHERE ebd.emp_no_int = aed.emp_no_int AND aed.emp_no_int = eod.emp_no_int AND ebd.emp_no_int = :empNo")
    List<EmpBoardingHistory> getEmpBoardingDetails(@Param("empNo") long empNo); 
}

2。 EmpBoardingHistory.java：

@Entity
@Table(name = "emp_boarding_history")
public class EmpBoardingHistory implements Serializable {
    private static final long serialVersionUID = 1L;

    public EmpBoardingHistory() {
        super();
    }

    public EmpBoardingHistory(String exemptionfromaxpreporting, String exemptionremarks,
            @NotNull(message = "Employee number is mandatory") @Range(min = 999, max = 999999999) int empno,
            String firstname, String middlename, String lastname, String emailid, String emporcontractor,
            String venderlaptopordesktopassetno, String countryoforigin, String status, String billponumber,
            String contractoridnumber, String contracttype, String projmastercd, String amexemailaddress,
            String amexlaptopordesktopassetnumber, String adsid, String costcenter, Date contractoridcreationdate,
            Date firstbillingdate, String clarityorresourcerole, String premiumtechnology, String resourcestatus,
            Date onboardCompletionDate, Date resourceleavingdate,
            @NotNull(message = "First Billing Date is mandatory") Date departuredate) {
        super();
        this.exemptionfromaxpreporting = exemptionfromaxpreporting;
        this.exemptionremarks = exemptionremarks;
.......

//For all setter and getter defined
}}

当我尝试调用此 getEmpBoardingDetails() 时，出现以下异常：

020-06-03 16:24:15.146 DEBUG 68096 --- [nio-8080-exec-5] org.hibernate.SQL                        : SELECT new com.boarding.boardinghistory.resource.EmpBoardingHistory(ebd.exemption_type_txt, ebd.exemption_remarks_txt, ebd.emp_no_int, ebd.first_name_txt, ebd.middle_name_txt, ebd.last_name_txt, ebd.email_id_txt, ebd.emp_or_contractor_ind, ebd.vendor_laptop_desktop_asset_txt, ebd.country_origin_txt, ebd.status_txt, aed.billing_po_no_txt, aed.contractor_id_txt, aed.contract_type_txt, aed.proj_master_cd_txt, aed.amex_email_id_txt, aed.amex_laptop_desktop_asset_id_txt, aed.ads_id_txt, aed.cost_center_txt, aed.contractor_id_creation_date, aed.first_billing_date, aed.clarity_resource_role_txt, aed.platform_id_txt, aed.premium_technology_txt, aed.resource_status_txt, aed.onboard_completion_date, eod.resource_leaving_date, eod.departure_date) FROM emp_boarding_details ebd, amex_emp_details aed, emp_offboarding_details eod WHERE ebd.emp_no_int = aed.emp_no_int AND aed.emp_no_int = eod.emp_no_int AND ebd.emp_no_int = ?
2020-06-03 16:24:15.149 TRACE 68096 --- [nio-8080-exec-5] o.h.type.descriptor.sql.BasicBinder      : binding parameter [1] as [BIGINT] - [909089]
2020-06-03 16:24:15.282  WARN 68096 --- [nio-8080-exec-5] o.h.engine.jdbc.spi.SqlExceptionHelper   : SQL Error: 1064, SQLState: 42000
2020-06-03 16:24:15.282 ERROR 68096 --- [nio-8080-exec-5] o.h.engine.jdbc.spi.SqlExceptionHelper   : You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '.boarding.boardinghistory.resource.EmpBoardingHistory(ebd.exemption_type_txt, eb' at line 1

上述问题的继续-> 现在我能够成功地从多个表中检索数据（感谢 Jens！）但是当我尝试将该响应保存到另一个表中时，即 emp_boarding_history，数据没有持久化。

//检索并保存逻辑

public EmpBoardingHistory selectSaveEmpBoardingHistory(Integer empNo) { 
    //Retrieve Data FROM ONE TABLE 
    List<EmpBoardingHistory> empBoardingHistoryList = empBoardingHistoryRepository.findBoardingHistoryEmpNo(empNo); 
    EmpBoardingHistory empBoardingHistory = new EmpBoardingHistory(); 
    for (EmpBoardingHistory empBoardingHistoryObj : empBoardingHistoryList) 
    { 
    //SAVING DATA INTO ANOTHER TABLE 
    empBoardingHistoryRepository.save(empBoardingHistoryObj);
    empBoardingHistory = empBoardingHistoryObj; 
    } 
    return empBoardingHistory; 
    }

Answer 1

您在查询中使用了构造函数表达式：

new com.boarding.boardinghistory.resource.EmpBoardingHistory**(...

这是来自 JPQL 的构造。 但是您也将其标记为nativeQuery = true，这意味着它被解释为SQL，而SQL 没有这样的构造。 使用构造函数表达式或将其标记为本机查询，而不是两者。

此外，构造函数表达式包含 ** 这将不起作用。