此時如何在Query上使用？ -JPA存儲庫春季啟動

Question

我要做的是獲取每個月的總數。 因此，我提出了這些查詢。 我使用@Query關注了Spring Boot JPA存儲庫中的文檔。 但是，當我運行我的應用程序時，應用程序啟動失敗。 我不知道我的查詢是否正確。

這是我的@Query

    @Query("SELECT MONTH(date_completed) FROM shipment WHERE YEAR(date_created)=?1 GROUP BY MONTH(date_completed)=?1")
public List<Shipment> findByDate_completed(String date);

@Query("SELECT COUNT(*) FROM shipment WHERE YEAR(date_created)=?1 GROUP BY MONTH(date_completed)=?1")
public List<Shipment> countByDate_completed(String date);

Shipment.java

    package com.pahrsek.smartfleet.model;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.EnumType;
import javax.persistence.Enumerated;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Table;

import com.fasterxml.jackson.annotation.JsonIgnore;


/**
 * Delivery of goods
 * @author JRDomingo
 *
 */
@Entity
@Table(name="shipment")
public class Shipment {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    public Long id;

    @Column(name="booking_number",unique=true)
    public String bookingNumber;

    @Column(name="wb_number")
    public String wbNumber;

    @ManyToOne
    @JoinColumn(name="vehicle_id", referencedColumnName="id")
    public Vehicle vehicle;

    @ManyToOne
    @JoinColumn(name="customer_id", referencedColumnName="id")
    public Customer customer;

    public String origin;

    public String depot;

    @ManyToOne
    @JoinColumn(name="vendor_id", referencedColumnName="id")
    public Vendor vendor;

    public String type;

    @Column(name="commodity_type")
    public String commodityType;

    @Column(name="truck_type")
    public String truckType;

    @Enumerated(EnumType.STRING)
    public Status status;

    @Column(name="delivery_date")
    public Date deliveryDate;

    @Column(name="fuel_po")
    public String fuelPo;

    @Column(name="client_ref_no")
    public String clientReferenceNumber;

    public String remarks;

    @ManyToOne
    @JoinColumn(name="driver_id",referencedColumnName="id")
    public Personnel driver;

    @ManyToOne
    @JoinColumn(name="helper1_id",referencedColumnName="id")
    public Personnel helper1;

    @ManyToOne
    @JoinColumn(name="helper2_id",referencedColumnName="id")
    public Personnel helper2;


    public enum Status{
        New, Dispatched, Delivered, Completed, Cancelled
    }

    /******
     * ACTUAL DATES IMPLEMENTED
     ******/
    @Column(name="date_created")
    public Date dateCreated;

    @Column(name="date_dispatched")
    public Date dateDispatched;

    @Column(name="date_completed")
    public Date dateCompleted;

    @Column(name="date_cancelled")
    public Date dateCancelled;

    @Column(name="date_received")
    public Date dateReceived;

    @Column(name="farthest_destination")
    public String farthestDestination;

    @Column(name="client_rate")
    public Double clientRate;

    @Column(name="is_sub_con")
    public boolean isSubCon;

    @Column(name="sub_con_rate")
    public Double subConRate;

    @Column(name="fuel")
    public Double fuel;

    @Column(name="fuel_amount")
    public Double fuelAmount;

    @Column(name="route_code")
    public String routeCode;

    @ManyToOne
    @JsonIgnore
    @JoinColumn(name="dispatched_odometer_id",referencedColumnName="id")
    public RegularOdometerUsage dispatchedOdometer;

    @ManyToOne
    @JsonIgnore
    @JoinColumn(name="delivered_odometer_id",referencedColumnName="id")
    public RegularOdometerUsage deliveredOdometer;

    @ManyToOne
    @JsonIgnore
    @JoinColumn(name="completed_odometer_id",referencedColumnName="id")
    public RegularOdometerUsage completedOdometer;


    /**
     * index 0 = Driver , index 1 = Helper1, index 2 = Helper2
     */
    @JsonIgnore
    @OneToMany(mappedBy="shipment",targetEntity=PersonnelRate.class)
    public List<PersonnelRate> personnelRates = new ArrayList<PersonnelRate>();

    @JsonIgnore
    @ManyToOne
    @JoinColumn(name="company_id", referencedColumnName="id")
    public Company company;


    @JsonIgnore
    @ManyToOne
    @JoinColumn(name="prepared_user_id", referencedColumnName="id")
    public User preparedBy;


    @JsonIgnore
    @ManyToOne
    @JoinColumn(name="customer_invoice", referencedColumnName="id")
    public CustomerInvoice customerInvoice;

    @JsonIgnore
    @ManyToOne
    @JoinColumn(name="trucker_settlement", referencedColumnName="id")
    public TruckerSettlement truckerSettlement;

}

我要實現的是根據當前年份獲得每月狀態為“已完成”的發貨數量。

Answer 1

如果需要從數據庫中獲取自定義信息（例如，月數和相關記錄的數量），則無法從查詢方法返回整個實體。 您必須使用投影 。 例如：

public interface MonthAndCount {
    Integer getMonth();
    Long getCount();
}

@Query("select month(s.dateCompleted) as month, count(s.id) as count from Shipment s where year(s.dateCompleted) = ?1 group by month(s.dateCompleted)")
List<MonthAndCount> getMonthAndCount(int year);

注意：在此處使用別名（ as month或as count ）很重要，以使框架知道如何填充您的投影。

測試：

@Test
public void getMonthAndCount() {
    List<MonthAndCount> monthAndCount = repo.getMonthAndCount(2017);
    assertThat(monthAndCount).hasSize(4);
    monthAndCount.forEach(System.out::println);
}

結果：

{month=1, count=1}
{month=2, count=1}
{month=3, count=1}
{month=12, count=2}

Answer 2

在這種情況下，如果在hql查詢中執行select *操作，則hibernate可以將表數據映射到您的實體類，但是如果您通過執行某些操作選擇自定義字段，則需要創建那些映射該數據的投影類。

但是，在這種情況下，如果您不想創建任何類來從查詢中獲取數據，則可以使用Object[]代替實體類。

所以您的方法將看起來像這樣

@Query("SELECT MONTH(date_completed), COUNT(*) FROM shipment WHERE YEAR(date_created)=?1 GROUP BY MONTH(date_completed)=?1")
public List<Object[]> findByDate_completed(String date);