JPA複雑クエリ-Querydsl

依存の追加

      
            <dependency>  
                <groupId>com.querydslgroupId>  
                <artifactId>querydsl-jpaartifactId>  
            dependency>  
            <dependency>  
                <groupId>com.querydslgroupId>  
                <artifactId>querydsl-aptartifactId>  
                <scope>providedscope>  
            dependency>  

    <plugin>  
                    <groupId>com.mysema.mavengroupId>  
                    <artifactId>apt-maven-pluginartifactId>  
                    <version>1.1.3version>  
                    <executions>  
                        <execution>  
                            <goals>  
                                <goal>processgoal>  
                            goals>  
                            <configuration>  
                                <outputDirectory>target/generated-sources/javaoutputDirectory>  
                                <processor>com.querydsl.apt.jpa.JPAAnnotationProcessorprocessor>  
                            configuration>  
                        execution>  
                    executions>  
                plugin>  

 
mvn compileを実行すると、Queryエンティティが生成されます.
 
単一テーブルクエリ

package com.chhliu.springboot.jpa.repository;

import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import javax.transaction.Transactional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Component;

import com.chhliu.springboot.jpa.entity.QUser;
import com.chhliu.springboot.jpa.entity.User;
import com.querydsl.core.types.Predicate;
import com.querydsl.jpa.impl.JPAQueryFactory;

/**
 *   ：QueryDSL JPA
 * @author chhliu
 */
@Component
@Transactional
public class UserRepositoryManagerDsl {
    @Autowired
    private UserRepositoryDls repository;
    
    @Autowired
    @PersistenceContext
    private EntityManager entityManager;

        private JPAQueryFactory queryFactory;
    
     @PostConstruct
     public void init() {
        queryFactory = new JPAQueryFactory(entityManager);
     }

       public User findUserByUserName(final String userName){
         /**
         *      spring data QueryDSL  
         */
        QUser quser = QUser.user;
        Predicate predicate = quser.name.eq(userName);
        return repository.findOne(predicate);
    }
    
    /**
     * attention:
     * Details：  user       
     */
    public List findAll(){
        QUser quser = QUser.user;
        return queryFactory.selectFrom(quser)
                    .fetch();
    }
    
    /**
     * Details：     
     */
    public User findOneByUserName(final String userName){
        QUser quser = QUser.user;
        return queryFactory.selectFrom(quser)
            .where(quser.name.eq(userName))
            .fetchOne();
    }
    
    /**
     * Details：       
     */
    public User findOneByUserNameAndAddress(final String userName, final String address){
        QUser quser = QUser.user;
        return queryFactory.select(quser)
            .from(quser) //          selectFrom
            .where(quser.name.eq(userName).and(quser.address.eq(address)))//        where(quser.name.eq(userName), quser.address.eq(address))
            .fetchOne();
    }
    
    /**
     * Details：  join  
     */
    public List findUsersByJoin(){
        QUser quser = QUser.user;
        QUser userName = new QUser("name");
        return queryFactory.selectFrom(quser)
            .innerJoin(quser)
            .on(quser.id.intValue().eq(userName.id.intValue()))
            .fetch();
    }
    
    /**
     * Details：       
     */
    public List findUserAndOrder(){
        QUser quser = QUser.user;
        return queryFactory.selectFrom(quser)
            .orderBy(quser.id.desc())
            .fetch();
    }
    
    /**
     * Details：Group By  
     */
    public List findUserByGroup(){
        QUser quser = QUser.user;
        return queryFactory.select(quser.name)
                    .from(quser)
                    .groupBy(quser.name)
                    .fetch();
    }
    
    /**
     * Details：    
     */
    public long deleteUser(String userName){
        QUser quser = QUser.user;
        return queryFactory.delete(quser).where(quser.name.eq(userName)).execute();
    }
    
    /**
     * Details：    
     */
    public long updateUser(final User u, final String userName){
        QUser quser = QUser.user;
        return queryFactory.update(quser).where(quser.name.eq(userName))
            .set(quser.name, u.getName())
            .set(quser.age, u.getAge())
            .set(quser.address, u.getAddress())
            .execute();
    }
    
    /**
     * Details：    Query
     */
    public User findOneUserByOriginalSql(final String userName){
        QUser quser = QUser.user;
        Query query = queryFactory.selectFrom(quser)
                .where(quser.name.eq(userName)).createQuery();
        return (User) query.getSingleResult();
    }
    
    /**
     * Details：      
     */
    public Page findAllAndPager(final int offset, final int pageSize){
        Predicate predicate = QUser.user.id.lt(10);
        Sort sort = new Sort(new Sort.Order(Sort.Direction.DESC, "id"));
        PageRequest pr = new PageRequest(offset, pageSize, sort);
        return repository.findAll(predicate, pr);
    }
}

 
マルチテーブル操作例(1対1)

package com.chhliu.springboot.jpa.repository;

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

import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.chhliu.springboot.jpa.dto.PersonIDCardDto;
import com.chhliu.springboot.jpa.entity.QIDCard;
import com.chhliu.springboot.jpa.entity.QPerson;
import com.querydsl.core.QueryResults;
import com.querydsl.core.Tuple;
import com.querydsl.core.types.Predicate;
import com.querydsl.jpa.impl.JPAQuery;
import com.querydsl.jpa.impl.JPAQueryFactory;

@Component
public class PersonAndIDCardManager {
    @Autowired
    @PersistenceContext
    private EntityManager entityManager;
    
    private JPAQueryFactory queryFactory;
    
    @PostConstruct
    public void init() {
        queryFactory = new JPAQueryFactory(entityManager);
    }
    
    /**
     * Details：      
     */
    public List findAllPersonAndIdCard(){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        JPAQuery jpaQuery = queryFactory.select(QIDCard.iDCard.idNo, QPerson.person.address, QPerson.person.name)
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate);
        return jpaQuery.fetch();
    }
    
    /**
     * Details：      DTO     
     */
    public List findByDTO(){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        JPAQuery jpaQuery = queryFactory.select(QIDCard.iDCard.idNo, QPerson.person.address, QPerson.person.name)
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate);
        List tuples = jpaQuery.fetch();
        List dtos = new ArrayList();
        if(null != tuples && !tuples.isEmpty()){
            for(Tuple tuple:tuples){
                String address = tuple.get(QPerson.person.address);
                String name = tuple.get(QPerson.person.name);
                String idCard = tuple.get(QIDCard.iDCard.idNo);
                PersonIDCardDto dto = new PersonIDCardDto();
                dto.setAddress(address);
                dto.setIdNo(idCard);
                dto.setName(name);
                dtos.add(dto);
            }
        }
        return dtos;
    }
    
    /**
     * Details：      ，   
     */
    public QueryResults findByDtoAndPager(int offset, int pageSize){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        return queryFactory.select(QIDCard.iDCard.idNo, QPerson.person.address, QPerson.person.name)
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate)
                .offset(offset)
                .limit(pageSize)
                .fetchResults();
    }
}

クエリ結果をDTOで出力した例では、クエリが終了すると、クエリ結果をDTOオブジェクトに手動で変換します.この方法はあまり優雅ではありません.QueryDSLは、次の例を参照してください.
 

/**
     * Details：   ：  Bean  
     */
    public List findByDTOUseBean(){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        return queryFactory.select(
                Projections.bean(PersonIDCardDto.class, QIDCard.iDCard.idNo, QPerson.person.address, QPerson.person.name))
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate)
                .fetch();
    }
    
    /**
     * Details：   ：  fields   setter
     */
    public List findByDTOUseFields(){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        return queryFactory.select(
                Projections.fields(PersonIDCardDto.class, QIDCard.iDCard.idNo, QPerson.person.address, QPerson.person.name))
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate)
                .fetch();
    }
    
    /**
     * Details：   ：      ，                        
     */
    public List findByDTOUseConstructor(){
        Predicate predicate = (QPerson.person.id.intValue()).eq(QIDCard.iDCard.person.id.intValue());
        return queryFactory.select(
                Projections.constructor(PersonIDCardDto.class, QPerson.person.name, QPerson.person.address, QIDCard.iDCard.idNo))
                .from(QIDCard.iDCard, QPerson.person)
                .where(predicate)
                .fetch();
    }

上記はいくつかのアイデアを提供しているだけで、もちろん@QueryProjectionを使って実現することもでき、非常に柔軟です.1対の複数の例:

package com.chhliu.springboot.jpa.repository;

import java.util.List;

import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.chhliu.springboot.jpa.entity.QOrder;
import com.chhliu.springboot.jpa.entity.QOrderItem;
import com.querydsl.core.Tuple;
import com.querydsl.core.types.Predicate;
import com.querydsl.jpa.impl.JPAQuery;
import com.querydsl.jpa.impl.JPAQueryFactory;

@Component
public class OrderAndOrderItemManager {
    
    @Autowired
    @PersistenceContext
    private EntityManager entityManager;
    
    private JPAQueryFactory queryFactory;
    
    @PostConstruct
    public void init() {
        queryFactory = new JPAQueryFactory(entityManager);
    }
    
    /**
     * Details：   ，    
     */
    public List findOrderAndOrderItemByOrderName(String orderName){
        //      
        Predicate predicate = QOrder.order.orderName.eq(orderName);
        JPAQuery jpaQuery = queryFactory.select(QOrder.order, QOrderItem.orderItem)
                                        .from(QOrder.order, QOrderItem.orderItem)
                                        .where(QOrderItem.orderItem.order.id.intValue().eq(QOrder.order.id.intValue()), predicate);
        
        //    
        return jpaQuery.fetch();
    }
    
    /**
     * Details：      
     */
    public List findAllByOrderName(String orderName){
        //      
        Predicate predicate = QOrder.order.orderName.eq(orderName);
        JPAQuery jpaQuery = queryFactory.select(QOrder.order, QOrderItem.orderItem)
                                        .from(QOrder.order, QOrderItem.orderItem)
                                        .rightJoin(QOrder.order)
                                        .on(QOrderItem.orderItem.order.id.intValue().eq(QOrder.order.id.intValue()));
        jpaQuery.where(predicate);
        //    
        return jpaQuery.fetch();
    }
}

 
 
リンク
Querydsl Reference Guide
QueryDSLの使用
複雑なクエリーのカプセル化
Spring boot-jpaはQueryDSLを統合して複雑な操作を簡略化する
Spring Boot JPA-Querydslを使用して複雑な操作を処理
転載先:https://www.cnblogs.com/tonyq/p/7881142.html