自定义sql语句多表连接查询+分页

Author: Snailclimb

docs/basis/springboot-jpa.md

@@ -312,13 +312,6 @@ public class PersonRepositoryTest {
         personRepository.deleteAll();
     }
 
-    @Sql(scripts = {"classpath:/init.sql"})
-    @Test
-    public void find_person_age_older_than_18() {
-        List<Person> personList = personRepository.findByAgeGreaterThan(18);
-        System.out.println(personList.toString());
-    }
-
 }
 ```
 

source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/model/dto/UserDTO.java

@@ -0,0 +1,17 @@
+package github.snailclimb.jpademo.model.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@Builder(toBuilder = true)
+@AllArgsConstructor
+public class UserDTO {
+    private String name;
+    private int age;
+    private String companyName;
+    private String schoolName;
+}

source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/model/po/Company.java

@@ -0,0 +1,28 @@
+package github.snailclimb.jpademo.model.po;
+
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+@Data
+@NoArgsConstructor
+public class Company {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(unique = true)
+    private String companyName;
+    private String description;
+
+    public Company(String name, String description) {
+        this.companyName = name;
+        this.description = description;
+    }
+}

source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/model/po/Person.java

@@ -0,0 +1,32 @@
+package github.snailclimb.jpademo.model.po;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class Person {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+    @Column(unique = true)
+    private String name;
+    private Integer age;
+    private Long companyId;
+    private Long schoolId;
+
+    public Person(String name, Integer age, Long companyId) {
+        this.name = name;
+        this.age = age;
+        this.companyId = companyId;
+    }
+}

source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/entity/Person.java renamed to source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/model/po/School.java

@@ -1,5 +1,8 @@
-package github.snailclimb.jpademo.entity;
+package github.snailclimb.jpademo.model.po;
 
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
@@ -12,17 +15,12 @@
 @Entity
 @Data
 @NoArgsConstructor
-public class Person {
+@AllArgsConstructor
+public class School {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long id;
     @Column(unique = true)
     private String name;
-    private Integer age;
-
-    public Person(String name, Integer age) {
-        this.name = name;
-        this.age = age;
-    }
-
+    private String description;
 }

source-code/basis/jpa-demo/src/main/java/github/snailclimb/jpademo/repository/PersonRepository.java

@@ -1,6 +1,9 @@
 package github.snailclimb.jpademo.repository;
 
-import github.snailclimb.jpademo.entity.Person;
+import github.snailclimb.jpademo.model.po.Person;
+import github.snailclimb.jpademo.model.dto.UserDTO;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.data.jpa.repository.Modifying;
 import org.springframework.data.jpa.repository.Query;
@@ -31,4 +34,22 @@ public interface PersonRepository extends JpaRepository<Person, Long> {
     @Transactional
     @Query("update Person p set p.name = ?1 where p.id = ?2")
     void updatePersonNameById(String name, Long id);
+
+    /**
+     * 连表查询
+     */
+    @Query(value = "select new github.snailclimb.jpademo.model.dto.UserDTO(p.name,p.age,c.companyName,s.name) " +
+            "from Person p left join Company c on  p.companyId=c.id " +
+            "left join School s on p.schoolId=s.id " +
+            "where p.id=:personId")
+    Optional<UserDTO> getUserInformation(@Param("personId") Long personId);
+
+    @Query(value = "select new github.snailclimb.jpademo.model.dto.UserDTO(p.name,p.age,c.companyName,s.name) " +
+            "from Person p left join Company c on  p.companyId=c.id " +
+            "left join School s on p.schoolId=s.id ",
+            countQuery = "select count(p.id) " +
+                    "from Person p left join Company c on  p.companyId=c.id " +
+                    "left join School s on p.schoolId=s.id ")
+    Page<UserDTO> getUserInformationList(Pageable pageable);
+
 }

source-code/basis/jpa-demo/src/main/resources/application.properties

@@ -12,4 +12,3 @@ spring.jpa.hibernate.ddl-auto=create
 spring.jpa.open-in-view=false
 # 创建的表的 ENGINE 为 InnoDB
 spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL55Dialect
-

source-code/basis/jpa-demo/src/test/java/github/snailclimb/jpademo/repository/PersonRepositoryTest.java

@@ -1,12 +1,11 @@
 package github.snailclimb.jpademo.repository;
 
-import github.snailclimb.jpademo.entity.Person;
+import github.snailclimb.jpademo.model.po.Person;
 import org.junit.Before;
 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.test.context.jdbc.Sql;
 import org.springframework.test.context.junit4.SpringRunner;
 
 import java.util.List;
@@ -30,11 +29,8 @@ public class PersonRepositoryTest {
     @Before
     public void setUp() {
         assertNotNull(personRepository);
-        Person person = new Person("SnailClimb", 23);
-        Person savedPerson = personRepository.saveAndFlush(person);// 更新 person 对象的姓名
-        savedPerson.setName("UpdatedName");
-        personRepository.save(savedPerson);
-
+        Person person = new Person("SnailClimb", 23, 1L);
+        Person savedPerson = personRepository.saveAndFlush(person);
         id = savedPerson.getId();
     }
 
@@ -76,11 +72,5 @@ public void should_get_person_use_custom_query() {
         personRepository.deleteAll();
     }
 
-    @Sql(scripts = {"classpath:/init.sql"})
-    @Test
-    public void find_person_age_older_than_18() {
-        List<Person> personList = personRepository.findByAgeGreaterThan(18);
-        System.out.println(personList.toString());
-    }
 
 }

source-code/basis/jpa-demo/src/test/java/github/snailclimb/jpademo/repository/PersonRepositoryTest2.java

@@ -0,0 +1,52 @@
+package github.snailclimb.jpademo.repository;
+
+import github.snailclimb.jpademo.model.dto.UserDTO;
+import github.snailclimb.jpademo.model.po.Person;
+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.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.test.context.jdbc.Sql;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.util.List;
+import java.util.Optional;
+
+import static org.junit.Assert.assertEquals;
+
+@SpringBootTest
+@RunWith(SpringRunner.class)
+public class PersonRepositoryTest2 {
+    @Autowired
+    private PersonRepository personRepository;
+
+    @Sql(scripts = {"classpath:/init.sql"})
+    @Test
+    public void find_person_age_older_than_18() {
+        List<Person> personList = personRepository.findByAgeGreaterThan(18);
+        assertEquals(1, personList.size());
+    }
+
+    @Sql(scripts = {"classpath:/init.sql"})
+    @Test
+    public void should_get_user_info() {
+        Optional<UserDTO> userInformation = personRepository.getUserInformation(1L);
+        System.out.println(userInformation.get().toString());
+    }
+
+    @Sql(scripts = {"classpath:/init.sql"})
+    @Test
+    public void should_get_user_info_list() {
+        PageRequest pageRequest = PageRequest.of(0, 3, Sort.Direction.DESC, "age");
+        Page<UserDTO> userInformationList = personRepository.getUserInformationList(pageRequest);
+        //查询结果总数
+        System.out.println(userInformationList.getTotalElements());// 6
+        //按照当前分页大小，总页数
+        System.out.println(userInformationList.getTotalPages());// 2
+        System.out.println(userInformationList.getContent());
+    }
+}

source-code/basis/jpa-demo/src/test/resources/init.sql

@@ -1,8 +1,14 @@
-insert into person (name, age) values ("person1","18")
-insert into person (name, age) values ("person2","16")
-insert into person (name, age) values ("person3","15")
-insert into person (name, age) values ("person4","13")
-insert into person (name, age) values ("person5","18")
-insert into person (name, age) values ("person6","18")
-insert into person (name, age) values ("person7","18")
-insert into person (name, age) values ("person8","18")
+insert into person (name, age,company_id,school_id)  values ("person1",18,1,1)
+insert into person (name, age,company_id,school_id)  values ("person2",18,1,1)
+insert into person (name, age,company_id,school_id)  values ("person3",15,1,1)
+insert into person (name, age,company_id,school_id)  values ("person4",18,2,2)
+insert into person (name, age,company_id,school_id)  values ("person5",16,2,2)
+insert into person (name, age,company_id,school_id)  values ("person6",19,2,2)
+
+
+insert into company (company_name, description) values ("tw","tw is good")
+insert into company (company_name, description) values ("baidu","baidu is good")
+
+insert into school (name, description) values ("zhongnandaxue","zhongnandaxue is good")
+insert into school (name, description) values ("hubeidaxue","hubeidaxue is good")
+