MongoDB学习(四)MongoDB整合SpringData

Z时代
2024-01-10
分类：综合

database

1、环境搭建

步骤一：修改pom文件，更新依赖

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>
<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
</dependency>

步骤二：修改yml文件，配置 mongo连接字符串

spring: data: mongodb: uri: mongodb://root:1234@localhost:27017/admin

步骤三：编写 JavaBean，配置文档对应集合

package com.tqyl.domain;
import lombok.Data;
import org.springframework.data.annotation.Id;
import org.springframework.data.mongodb.core.mapping.Document;
import org.springframework.data.mongodb.core.mapping.Field;
/**
 * @author 庭前云落
 * @Date 2020/6/16 8:50
 * @description
 */
@Data
@Document(collection = "teacher")
public class Teacher {
    @Id
    private String teacherId;
    @Field("username")
    private String username;
    private String password;
    private Integer age;
    public Teacher() {
    }
    public Teacher(String teacherId, String username, String password, Integer age) {
        this.teacherId = teacherId;
        this.username = username;
        this.password = password;
        this.age = age;
    }
}

步骤四：编写 dao，继承MongoRepository

package com.tqyl.dao;
import com.tqyl.domain.Teacher;
import org.springframework.data.mongodb.repository.MongoRepository;
import java.util.List;
/**
 * @author 庭前云落
 * @Date 2020/6/16 8:51
 * @description
 */
public interface TeacherDao extends MongoRepository<Teacher,String> {
    public List<Teacher> findByUsername(String username);
}

步骤五：编写启动类，使用@ComponentScan扫描 dao

package com.tqyl;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
/**
 * @author 庭前云落
 * @Date 2020/6/16 8:52
 * @description
 */
@SpringBootApplication
@ComponentScan(basePackages = "com.tqyl.dao")
public class TestApplication {
    public static void main(String[] args) {
        SpringApplication.run(TestApplication.class,args);
    }
}

步骤六：编写测试类，获得 dao 实现类

@RunWith(SpringRunner.class)
@SpringBootTest(classes = TestApplication.class)
public class TestRepository {
    @Resource
    private TeacherDao teacherDao;
}

2、基础操作

2.1、查询所有

   @Test
    public void testFindAll(){
        //查询
        List<Teacher> list = teacherDao.findAll();
        System.out.println(list);
    }

2.2、排序查询

   @Test
    public void testDemo01(){
        //排序
        //List<Teacher> list = teacherRepository.findAll(Sort.by("password"));
        List<Teacher> list = teacherDao.findAll(Sort.by(Sort.Order.desc("password")));
        for (Teacher teacher : list) {
            System.out.println(teacher);
        }
    }

2.3、分页

分页基本操作

    @Test
    public void testDemo02(){
        //分页
        int page = 0;   //从0开始
        int size = 2;
        Page<Teacher> teacherPage = teacherDao.findAll(PageRequest.of(page, size));
        //处理分页数据
        //1 获得分页内容
        List<Teacher> list = teacherPage.getContent();
        //2 获得总记录数
        long total = teacherPage.getTotalElements();
        System.out.println("总条数：" + total);
        for (Teacher teacher : list) {
            System.out.println(teacher);
        }
    }

分页 jdk8 ForEach

    @Test
    public void testDemo03() {
        //分页
        int page = 0;   //从0开始
        int size = 2;
        Page<Teacher> teacherPage = teacherDao.findAll(PageRequest.of(page, size));
        //遍历数据
        // JDK8提供forEach，使用箭头函数进行遍历
        teacherPage.forEach(teacher -> System.out.println(teacher) );
        // 打印简化版
        teacherPage.forEach(System.out::println);
    }

2.5、添加

    @Test
    public void testDemo04(){
        //准备数据
        Teacher teacher = new Teacher();
        teacher.setUsername("王五");
        teacher.setPassword("666777");
        teacher.setAge(30);
        //插入数据
        teacherDao.insert( teacher );
    }

2.6、通过ID查询

    @Test
    public void testDemo05(){
        //通过id查询
        Optional<Teacher> optional = teacherDao.findById("5ee83ccf9d1c6904d8768ca8");
        //Optional 用于统一规范空指针异常处理
        if(optional.isPresent()){  // teacher != null
            Teacher teacher = optional.get();
            System.out.println(teacher);
        } else {
            System.out.println("没有数据");
        }
    }

2.7、更新

更新采用save方法
- 如果数据存在，将发生更新操作
- 如果数据不存在，将发生添加操作

    @Test
    public void testDemo06(){
        //更新操作
        //1 查询
        Optional<Teacher> optional = teacherDao.findById("5ee83ccf9d1c6904d8768ca8");
        if(optional.isPresent()) {
            //2 修改数据
            Teacher teacher = optional.get();
            teacher.setUsername("王武");
            //3 更新
            teacherDao.save(teacher);
        }
    }

2.8、删除

deleteById() ：通过id删除

deleteAll() ：删除所有

    @Test
    public void testDemo07(){
        //删除
        teacherDao.deleteById("5ee83ccf9d1c6904d8768ca8");
    }

2.9、自定义dao

在dao中，可以通过约定进行条件查询
- 前缀：findBy
- 查询条件：字段名
- 关键字：And、Or、Like 等

TeacherRepository

 public List<Teacher> findByUsername(String username);

    @Test
    public void testDemo08(){
        //自定义查询
        List<Teacher> list = teacherRepository.findByUsername("tom");
        System.out.println(list);
    }

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