springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁

springDataJpa入門教程

springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁

在JPA實際應用中，很多場景下需要同時對多個表進行操作，這時候，JPA提供的JPQL語句就無法滿足實際應用的需求，需要用到原生sql來實現查詢，簡單的原生sql查詢直接使用@Query註解就可以完成，但是要想實現多表並且動態條件查詢，則@Query註解也顯得力不從心，這時候EntityManager便派上用場了。

下面接着上一節的內容來講解如何使用EntityManager實現多表聯合查詢+動態條件查詢+分頁。有需要源碼的朋友，請到git上下載源碼，源碼地址：源碼下載地址。java學習交流羣：184998348,歡迎大家一起交流學習。

實體類分別是User類、Address類，下面這兩個類的代碼：

package com.thizgroup.jpa.study.model;

import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Entity
@Table(name = "tb_user")
@Data//使用lombok生成getter、setter
@NoArgsConstructor//生成無參構造方法
public class User {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  @Column(name = "name",columnDefinition = "varchar(64)")
  private String name;

  @Column(name = "mobile",columnDefinition = "varchar(64)")
  private String mobile;

  @Column(name = "email",columnDefinition = "varchar(64)")
  private String email;

  @Column(name = "age",columnDefinition = "smallint(64)")
  private Integer age;

  @Column(name = "birthday",columnDefinition = "timestamp")
  private Date birthday;

  //地址
  @Column(name = "address_id",columnDefinition = "bigint(20)")
  private Long addressId;

  @Column(name = "create_date",columnDefinition = "timestamp")
  private Date createDate;

  @Column(name = "modify_date",columnDefinition = "timestamp")
  private Date modifyDate;

  @Builder(toBuilder = true)
  public User(Long id,String name, String mobile, String email, Integer age, Date birthday,
      Long addressId) {
    this.id = id;
    this.name = name;
    this.mobile = mobile;
    this.email = email;
    this.age = age;
    this.birthday = birthday;
    this.addressId = addressId;
  }
}

package com.thizgroup.jpa.study.model;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Data;

@Entity
@Table(name="tb_address")
@Data//使用lombok生成getter、setter
public class Address {

  @Id
  @GeneratedValue(strategy = GenerationType.IDENTITY)
  private Long id;

  @Column(name = "country",columnDefinition = "varchar(64)")
  private String country;

  @Column(name = "province",columnDefinition = "varchar(64)")
  private String province;

  @Column(name = "city",columnDefinition = "varchar(64)")
  private String city;

}

涉及到DTO及輔助類

package com.thizgroup.jpa.study.dto;

import java.io.Serializable;
import java.util.List;
import lombok.Data;
import lombok.Getter;
import org.springframework.util.Assert;

@Data//使用lombok生成getter、setter
public class PageBean implements Serializable {

  @Getter
  private long totalCount;//總記錄數

  @Getter
  private int totalPages;//總頁數

  @Getter
  private int pageNumber;//第幾頁

  @Getter
  private int pageSize;//每頁條數

  public PageBean(int pageNumber, int pageSize, long totalCount) {

    pageNumber = pageNumber <0 ? 0 :pageNumber;//jpa中頁碼從0開始
    pageSize = pageSize <=0 ? 15 : pageSize;//默認取15條記錄

    //計算總頁數
    int totalPages = (int)((totalCount+pageSize-1)/pageSize);
    //計算起始頁
    if(totalPages>0){
      pageNumber = totalPages <= pageNumber ? totalPages-1 : pageNumber;
    }

    this.pageNumber = pageNumber;
    this.pageSize = pageSize;
    this.totalPages =  totalPages;
    this.totalCount = totalCount;

  }

  public PageBean(PageBean pageBean) {
    Assert.notNull(pageBean,"pagebean cannot be null");
    this.pageNumber = pageBean.getPageNumber();
    this.pageSize = pageBean.getPageSize();
    this.totalPages =  pageBean.getTotalPages();
    this.totalCount = pageBean.getTotalCount();
  }

}

package com.thizgroup.jpa.study.dto;

import java.util.List;
import lombok.Data;
import lombok.Getter;

@Data
public class PageRecord<T> extends PageBean {

  @Getter
  private List<T> data;//數據列表

  public PageRecord(int pageNumber, int pageSize, long totalCount,List<T> data) {
    super(pageNumber, pageSize, totalCount);
    this.data = data;
  }

  public PageRecord(PageBean pageBean, List<T> data){
    super(pageBean);
    this.data =data;
  }

}

package com.thizgroup.jpa.study.dto;

import java.util.Date;
import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data//使用lombok生成getter、setter
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class UserDTO {

  private Long id;

  private String name;//姓名

  private Integer age;//年齡

  private String mobile;//手機號

  private String email;//郵箱

  private Date birthday;//生日

  private AddressDTO addressDTO;//地址

  private Date createDate;//創建時間

  private Date modifyDate;//修改時間

  private Date startTime;//開始時間

  private Date endTime;//結束時間
}

package com.thizgroup.jpa.study.dto;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data//使用lombok生成getter、setter
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class AddressDTO {

  private Long id;

  private String country;//國家

  private String province;//省份

  private String city;//城市

}

1.需求：根據用戶名、年齡，生日（開始時間-結束時間）、城市名稱查詢用戶分頁列表，查詢結果按照用戶創建時間排序。

在IUserService接口中創建一個查詢方法，

package com.thizgroup.jpa.study.service;

import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserDTO;
import com.thizgroup.jpa.study.model.User;
import java.util.List;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;

/**
 * 用戶服務
 */
public interface IUserService {

  /**
   * 查詢用戶分頁信息
   * @param userDTO
   * @return
   */
  PageRecord<UserDTO> findUserDTOListByPage(UserDTO userDTO, Pageable pageable);
}

然後在UserServiceImpl中實現該方法，

package com.thizgroup.jpa.study.service.impl;

import com.thizgroup.jpa.study.dao.UserDao;
import com.thizgroup.jpa.study.dto.AddressDTO;
import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserDTO;
import com.thizgroup.jpa.study.model.User;
import com.thizgroup.jpa.study.service.IUserService;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.Assert;

@Service
@Transactional(readOnly = false,propagation = Propagation.REQUIRED)
public class UserServiceImpl implements IUserService {
  @Autowired
  private UserDao userDao;
  @Override
  public PageRecord<UserDTO> findUserDTOListByPage(UserDTO userDTO, Pageable pageable) {
    return userDao.findUserListByPage(userDTO,pageable);
  }

主要的代碼邏輯在dao層，讓我們來看下UserDao 的代碼，

package com.thizgroup.jpa.study.dao;

import com.thizgroup.jpa.study.dto.AddressDTO;
import com.thizgroup.jpa.study.dto.PageBean;
import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserDTO;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.Query;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Repository;

/**
 * 用戶服務
 */
@Repository
public class UserDao {

  @Autowired
  private EntityManager entityManager;

  //使用entityManager實現多表聯合帶條件帶分頁查詢及排序
  public PageRecord<UserDTO> findUserListByPage(UserDTO userDTO, Pageable pageable){

    List<Object> args = new ArrayList<>();//用於封裝參數

    StringBuffer sql = new StringBuffer();
    sql.append(
        " select u.id,u.name,u.age,u.birthday,u.mobile,u.email,a.country,a.province,a.city,"
            + " u.create_date "
            + " from tb_user u "
        + " left join  tb_address a on u.address_id = a.id "
            + " where 1=1 "
    );

    if(userDTO  != null){
      if(StringUtils.isNotBlank(userDTO.getName())){
        //模糊查詢
        sql.append(" and u.name like ? ");
        args.add("%"+userDTO.getName()+"%");
      }
      if(null != userDTO.getAge()){
        //精確查詢
        sql.append(" and u.age = ? ");
        args.add(userDTO.getAge());
      }
      //求生日在某個時間段範圍內的用戶
      if(null != userDTO.getStartTime()){
        //大於等於
        sql.append(" and u.birthday >= ? ");
        args.add(userDTO.getStartTime());
      }
      if(null != userDTO.getEndTime()){
        //小於等於
        sql.append(" and u.birthday <= ? ");
        args.add(userDTO.getEndTime());
      }

     if(userDTO.getAddressDTO() != null) {
       AddressDTO addressDTO = userDTO.getAddressDTO();
       //查詢某個城市的用戶
       if(StringUtils.isNotBlank(addressDTO.getCity())) {
         sql.append(" and a.city = ? ");
         args.add(addressDTO.getCity());
       }
     }

    }

    //按照創建時間倒序排序
    sql.append(" order by u.create_date desc ");

    //創建query對象
    Query query = entityManager.createNativeQuery(sql.toString());

    //設置查詢參數
    if(args.size()>0){
      for(int i=0;i<args.size();i++){
        //注意：jpa的setParameter是從1開始的
        query.setParameter(i+1,args.get(i));
      }
    }

    PageBean pageBean = findPageBean(sql.toString(), args, pageable);

    //分頁查詢
    query.setFirstResult(pageBean.getPageNumber()*pageBean.getPageSize());
    query.setMaxResults(pageBean.getPageNumber()*pageBean.getPageSize()+pageBean.getPageSize());
    List<Object[]> resultList = query.getResultList();

    //封裝查詢結果
    List<UserDTO> userDTOList = new ArrayList<>();
    if(resultList != null && resultList.size() > 0) {
      resultList.forEach(objs -> {
        UserDTO userDTONew = UserDTO.builder()
            .id(((BigInteger)objs[0]).longValue())
            .name((String) objs[1])
            .age(((Short) objs[2]).intValue())
            .birthday((Date) objs[3])
            .mobile((String) objs[4])
            .email((String) objs[5])
            .addressDTO(
                AddressDTO.builder()
                  .country((String) objs[6])
                  .province((String) objs[7])
                  .city((String) objs[8])
                  .build()
            )
            .createDate((Date) objs[9])
            .build();
        //添加到列表中
        userDTOList.add(userDTONew);
      });
    }

    return new PageRecord<UserDTO>(pageBean,userDTOList);
  }

  //查詢分頁信息
  PageBean findPageBean(String sql,List<Object> args,Pageable pageRequest){
    String countSql = " select count(*) from (" + sql + ") tb ";

    Query countQuery = entityManager.createNativeQuery(countSql);

    if(args != null && args.size()>0){
      for(int i=0;i<args.size();i++){
        countQuery.setParameter(i+1,args.get(i));
      }
    }

    //查詢總記錄數
    long totalCount = ((BigInteger)countQuery.getSingleResult()).longValue();

    return new PageBean(pageRequest.getPageNumber(),pageRequest.getPageSize(),totalCount);

  }

}

說大體思路，首先使用StringBuffer 來動態拼接查詢條件，使用List來封裝所有的查詢參數，根據sql語句查詢總記錄數，然後計算出分頁信息，再通過setFirstResult和setMaxResults設置查詢記錄的起始位置，最後通過循環將查詢的結果集封裝到對象中。

下面寫個單元測試驗證一下，

package com.thizgroup.jpa.study.service;

import com.thizgroup.jpa.study.JpaApplication;
import com.thizgroup.jpa.study.dto.AddressDTO;
import com.thizgroup.jpa.study.dto.PageRecord;
import com.thizgroup.jpa.study.dto.UserDTO;
import com.thizgroup.jpa.study.model.User;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.test.annotation.Rollback;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

@SpringBootTest(classes={JpaApplication.class})
@RunWith(SpringJUnit4ClassRunner.class)
@Transactional(readOnly = false,propagation = Propagation.REQUIRED)
public class UserServiceImplTest {
	  @Test
  public void findUserListByPage2Test() throws Exception {
    UserDTO userDTO = UserDTO.builder()
        .name("諸")
        //.age(35)
        //.startTime(dateFormat.parse("2001-09-16 08:00:00"))
        //.endTime(dateFormat.parse("2008-09-16 07:00:00"))
        .addressDTO(AddressDTO.builder()
            .city("武漢")
            .build())
        .build();
    //注意：jpa的分頁是從0開始的
    PageRecord<UserDTO> userListByPage2 = userService
        .findUserDTOListByPage(userDTO, PageRequest.of(0, 15));

    System.out.println("分頁信息：");
    System.out.println("總記錄數："+userListByPage2.getTotalCount()+",總頁數："+userListByPage2.getTotalPages());
    System.out.println("頁碼："+(userListByPage2.getPageNumber()+1)+",每頁條數："+userListByPage2.getPageSize());
    List<UserDTO> content = userListByPage2.getData();
    content = null == content? new ArrayList<>() : content;
    content.forEach(user->System.out.println(user));

  }
}

運行一下單元測試，結果如下：

分頁信息：
總記錄數：1,總頁數：1
頁碼：1,每頁條數：15
UserDTO(id=3, name=諸葛亮, age=54, mobile=158989989, email=zhu@qq.com, birthday=2001-09-16 08:00:00.0, addressDTO=AddressDTO(id=null, country=中國, province=湖北, city=武漢), createDate=2019-09-06 05:50:01.0, modifyDate=null, startTime=null, endTime=null)

至此，springDataJpa基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁就介紹完了，有需要源碼的朋友，請到git上下載源碼，源碼地址：https://github.com/hgq0916/springdatajpa-study.git。java學習交流羣：184998348,歡迎大家一起交流學習。

springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁

springDataJpa入門教程

springDataJpa入門教程（1）-基於springBoot的基本增刪改查

springDataJpa入門教程（2）-Specification動態條件查詢+排序+分頁

springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁

springDataJpa入門教程（3-2）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁返回自定義實體類對象

springDataJpa入門教程（4）-Example單表動態條件查詢+分頁

springDataJpa入門教程（5）-單表動態條件查詢+分頁

springDataJpa入門教程（6）-多表動態條件查詢+分頁

springDataJpa入門教程（7）-基於springDataJpa投影(Projection)返回自定義實體類對象

springDataJpa入門教程（8）-JPA EnableJpaAuditing 審計功能

springDataJpa入門教程（9）-spring jpa實體屬性類型轉換器AttributeConverter的用法

springDataJpa入門教程（10）-JPA使用過程中遇到的坑及解決方法

springDataJpa入門教程（3-1）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁

1.需求：根據用戶名、年齡，生日（開始時間-結束時間）、城市名稱查詢用戶分頁列表，查詢結果按照用戶創建時間排序。

上一篇：springDataJpa入門教程（2）-Specification動態條件查詢+排序+分頁

下一篇：springDataJpa入門教程（3-2）-基於EntityManager原生sql多表聯合查詢+動態條件查詢+分頁返回自定義實體類對象

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