JPA多條件複雜SQL動態分頁查詢

概述

　　ORM映射爲咱們帶來便利的同時，也失去了較大靈活性，若是SQL較複雜，要進行動態查詢，那一定是一件頭疼的事情（也多是lz還沒發現好的方法），記錄下本身用的三種複雜查詢方式。

環境

springBoot

IDEA2017.3.4

JDK8

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.xmlxy</groupId>
    <artifactId>seasgame</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>seasgame</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!--數據庫鏈接-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

        <!-- 熱啓動等 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>

        <!--Java bean 實體-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <!--swagger2 API 測試工具 -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.8.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
        <!--安全框架認證-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-security</artifactId>
        </dependency>
        <dependency>
            <groupId>net.sf.json-lib</groupId>
            <artifactId>json-lib</artifactId>
            <version>2.2.2</version>
            <classifier>jdk15</classifier>
        </dependency>
        <!--漢字轉拼音-->
        <dependency>
            <groupId>com.belerweb</groupId>
            <artifactId>pinyin4j</artifactId>
            <version>2.5.1</version>
        </dependency>
        <!-- thymeleaf模板 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <!-- <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> 移除嵌入式tomcat插件 <exclusions> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> </exclusion> </exclusions> </dependency> -->

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
    </dependencies>
    <packaging>war</packaging>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>

        <finalName>seasgame</finalName>
        <pluginManagement>
            <plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>2.3.2</version>
                    <configuration>
                        <encoding>${project.build.sourceEncoding}</encoding>
                        <source>1.7</source>
                        <target>1.7</target>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-surefire-plugin</artifactId>
                    <configuration>
                        <testFailureIgnore>true</testFailureIgnore>
                    </configuration>
                </plugin>
            </plugins>
        </pluginManagement>
    </build>

</project>

@Query

當一個SQL較爲複雜時，第一個想到的就是原生的SQL語句。若是隻是簡單的查詢，那狀況還沒這麼糟糕

@Query(value = " SELECT IFNULL(sum(right_num),0) sumRight FROM t_record WHERE record_owner_id = ?1 AND responder_no = ?2 ",nativeQuery = true) Map<String,Object> sumRightNum(int studentId,int responderNo);

但若是須要進行動態查詢，或更改，那這個value就變得複雜了。

package com.xmlxy.seasgame.dao; import com.xmlxy.seasgame.entity.ScoreEntity; import org.springframework.data.jpa.repository.Modifying; import org.springframework.data.jpa.repository.Query; import org.springframework.data.repository.CrudRepository; import org.springframework.data.repository.query.Param; import org.springframework.transaction.annotation.Transactional; import java.util.List; /** * * Description: * @author hwc * @date 2019/9/5 * @return
*/ 
public interface ScoreDao extends CrudRepository<ScoreEntity,Integer> { /** * * Description: *@param scoreEntity * @author hwc * @date 2019/9/6 */ @Transactional(rollbackFor = Exception.class) @Modifying @Query(value = "UPDATE t_score t SET " +
            "t.responder_no = CASE WHEN :#{#scoreEntity.responderNo} IS NULL THEN t.responder_no ELSE :#{#scoreEntity.responderNo} END," +
            "t.max_level = CASE WHEN :#{#scoreEntity.maxLevel} IS NULL THEN t.max_level ELSE :#{#scoreEntity.maxLevel} END," +
            "t.right_num = CASE WHEN :#{#scoreEntity.rightNum} IS NULL THEN t.right_num ELSE :#{#scoreEntity.rightNum} END," +
            "t.use_time = CASE WHEN :#{#scoreEntity.userTime} IS NULL THEN t.use_time ELSE :#{#scoreEntity.userTime} END WHERE student_id = :#{#scoreEntity.getStudentId()}",nativeQuery = true) void updateScore(@Param("scoreEntity") ScoreEntity scoreEntity); }

JPQL

若是Java代碼內發出JPQL查詢，就須要利用到EntityManager的響應方法了。通常執行如下流程

1. 獲取一個EntityManager實例
2. 調用實例的方法createQuery，建立一個Query實例，若是有須要能夠指定檢索的最大數量和起始位置
3. 使用Query方法getResultList執行查詢，固然更新和刪除操做得使用executeUpdate執行

進行一個複雜的動態SQL查詢

public Page<RankEntity> getScoreByRank(int gradeId,int classId,Pageable pageable)
    {
        StringBuilder countSelectSql = new StringBuilder("");
        countSelectSql.append(" SELECT COUNT(*) ");
        countSelectSql.append(" FROM ");
        countSelectSql.append(" t_score s, ");
        countSelectSql.append(" t_student st   ");
        countSelectSql.append(" WHERE ");
        countSelectSql.append(" s.student_id = st.student_id ");

        StringBuilder selectSql = new StringBuilder();
        selectSql.append(" SELECT s.student_id,st.real_name,st.student_class,s.max_level,s.use_time,s.right_num ");
        selectSql.append(" FROM t_score s ");
        selectSql.append(" JOIN t_student st ON s.student_id = st.student_id ");
        selectSql.append(" WHERE 1 = 1 ");
        Map<String,Object> params = new HashMap<>();
        StringBuilder whereSql = new StringBuilder();
        if (gradeId != -1)
        {
            whereSql.append(" AND st.student_grade = :student_grade ");
            params.put("student_grade",gradeId);
        }
        /**班級ID*/
        if (classId != -1)
        {
            whereSql.append(" AND st.student_class = :classId ");
            params.put("classId",classId);
        }
        String orderSql = " ORDER BY s.max_level DESC,s.use_time,s.right_num ASC ";
        String countSql = new StringBuilder().append(countSelectSql).append(whereSql).toString();
        Query countQuery = entityManager.createNativeQuery(countSql);
        for (Map.Entry<String,Object> entry : params.entrySet())
        {
            countQuery.setParameter(entry.getKey(),entry.getValue());
        }
        BigInteger totalCount = (BigInteger)countQuery.getSingleResult();

        String querySql = new StringBuilder().append(selectSql).append(whereSql).append(orderSql).toString();

        Query query = entityManager.createNativeQuery(querySql,RankEntity.class);
        for (Map.Entry<String,Object> entry:params.entrySet())
        {
            query.setParameter(entry.getKey(),entry.getValue());
        }
        query.setFirstResult((int) pageable.getOffset());
        query.setMaxResults(pageable.getPageSize());

        List<RankEntity> rankEntities = query.getResultList();
        Page<RankEntity> page = new PageImpl<>(rankEntities,pageable,totalCount.longValue());
        return page;
    }

注意：若是沒有從新定義Pageable那麼pageNumber必須減1，由於是從0開始的。

Criteria

這是一種規範查詢是以元模型的概念爲基礎的，這個元模型能夠是實體累，嵌入類，或者映射的父類，簡單介紹幾個裏面用到接口。

CriteraQuery是一個特定的頂層查詢對象，裏面包含select，from，where，order by等各個部分，然而他只對實體類或嵌入類的標準查詢起做用。

Root標準查詢的根對象，根定義了實體類型，是你想要查詢要得到的結果，也能夠添加查詢條件，結合實體管理對象獲得查詢的對象。

CriteriaBuilder接口用來構建CritiaQuery的構建器

 StudentEntity類

package com.xmlxy.seasgame.entity; import io.swagger.annotations.ApiModel; import lombok.Data; import javax.persistence.*; import javax.print.attribute.standard.MediaSize; import java.io.Serializable; /** * * Description:學生對象 * @param * @author hwc * @date 2019/8/8 */ @Entity @Table(name = "t_base_student") @ApiModel @Data public class StudentEntity implements Serializable { private static final long serialVersionUID = 546L; @Id @GeneratedValue(strategy = GenerationType.AUTO) @Column(name = "student_id") private Integer studentId; @Column(name = "student_grade") private Integer studentGrade; @Column(name = "student_class") private Integer studentClass; @Column(name = "address") private String address; @Column(name = "telephone") private Integer telephone; @Column(name = "real_name") private String realName; @Column(name = "id_number") private String idNumber; @Column(name = "study_id") private String studyId; @Column(name = "is_delete") private int isDelete; @Column(name = "uuid") private String uuid; }

dao層

public interface StudentDao extends JpaRepository<StudentEntity,Integer>,JpaSpecificationExecutor { }

動態查詢

public Page<StudentEntity> getTeacherClassStudent(int pageNumber,int pageSize,int gradeId, int classId,String keyword) { pageNumber = pageNumber < 0 ? 0 : pageNumber; pageSize = pageSize < 0 ? 10 : pageSize; Specification<StudentEntity> specification = new Specification<StudentEntity>() { @Override public Predicate toPredicate(Root<StudentEntity> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) { //page : 0 開始, limit : 默認爲 10
                List<Predicate> predicates = new ArrayList<>(); predicates.add(criteriaBuilder.equal(root.get("studentGrade"),gradeId)); predicates.add(criteriaBuilder.equal(root.get("studentClass"),classId)); if (!Constant.isEmptyString(keyword)) { predicates.add(criteriaBuilder.like(root.get("realName").as(String.class),"%" + keyword + "%")); } return criteriaBuilder.and(predicates.toArray(new Predicate[predicates.size()])); } }; /*studentId必須是實體類屬性與數據庫對應，不然報ropertyReferenceException異常*/ PageRequest page = new PageRequest(pageNumber,pageSize,Sort.Direction.ASC,"studentId"); Page<StudentEntity> pages = studentDao.findAll(specification,page); return pages; }

由於這個項目應用比較簡單，因此條件只有一個，若是條件較多，甚至能夠定義一個專門的類去接收拼接參數，而後判斷，成立就add進去。

轉載一篇寫得不錯的文章：https://blog.csdn.net/u010775025/article/details/80497986