SpringBoot整合MongoDB实现增删改查、复合查询-蒲公英云

SpringBoot整合MongoDB实现增删改查、复合查询

1、向pom.xml中添加依赖包

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

2、编辑application.yml

spring:
  data:
    mongodb:
      host: 192.168.58.129            //IP地址
      database: studentdb            //数据库名

3、编写实体类

解释一下以下用到的的几个注解：
@Id ：文档的唯一标识，在mongodb中为ObjectId，它是唯一的，通过时间戳+机器标识+进程ID+自增计数器（确保同一秒内产生的Id不会冲突）构成。
@Document ：把一个java类声明为mongodb的文档，可以通过collection参数指定这个类对应的文档。@Document(collection=”mongodb”) mongodb对应表

/** * 学生类 */
@Document(collection = "student")    //指定对应的表名
public class Student implements Serializable { 
    @Id
    private Integer id;
    private String name;
    private Integer age;
    private Integer gradeId;
    private Grade grade;
    public Grade getGrade() { 
        return grade;
    }
    public void setGrade(Grade grade) { 
        this.grade = grade;
    }
    public Integer getId() { 
        return id;
    }
    public void setId(Integer id) { 
        this.id = id;
    }
    public String getName() { 
        return name;
    }
    public void setName(String name) { 
        this.name = name;
    }
    public Integer getAge() { 
        return age;
    }
    public void setAge(Integer age) { 
        this.age = age;
    }
    public Integer getGradeId() { 
        return gradeId;
    }
    public void setGradeId(Integer gradeId) { 
        this.gradeId = gradeId;
    }
    @Override
    public String toString() { 
        return getId()+getName()+getAge()+getGradeId();
    }
}
/** * 年级类 */
public class Grade implements Serializable { 
    private Integer id;
    private String gradeName;
    public Integer getId() { 
        return id;
    }
    public void setId(Integer id) { 
        this.id = id;
    }
    public String getGradeName() { 
        return gradeName;
    }
    public void setGradeName(String gradeName) { 
        this.gradeName = gradeName;
    }
}

4、StudentDao接口
提供增删改查 MongoDB 接口

public interface StudentDao { 
    //查询所有
    List<Student> findAll();
    //增加
    void add(Student student);
    //删除
    void delete(Integer id);
    //修改
    void update(Student student);
    //符合查询——两表联查
    List<Map> fuhefind();
}

5、StudentDaoImpl实现类

@Component
public class StudentDaoImpl implements StudentDao { 
    @Autowired
    private MongoTemplate mongoTemplate;
    @Override
    public List<Student> findAll() { 
        return mongoTemplate.findAll(Student.class);
    }
    @Override
    public void add(Student student) { 
        mongoTemplate.save(student);
    }
    @Override
    public void delete(Integer id) { 
        Student student=mongoTemplate.findById(1,Student.class);
        mongoTemplate.remove(student);
    }
    @Override
    public void update(Student student) { 
        //修改的条件
        Query query = new Query(Criteria.where("id").is(student.getId()));
        //修改的内容
        Update update = new Update();
        update.set("name",student.getName());
        mongoTemplate.updateFirst(query,update,Student.class);
    }
    @Override
    public List<Map> fuhefind() { 
        LookupOperation lookupOperation=LookupOperation.newLookup().from("grade").localField("_id").foreignField("_id").as("grade");
        Aggregation aggregation=Aggregation.newAggregation(lookupOperation);
        List<Map> result=mongoTemplate.aggregate(aggregation,"student",Map.class).getMappedResults();
        return result;
    }
}

6、单元测试

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootMongdbApplicationTests { 
    @Autowired
    private StudentDao studentDao;
    @Test
    public void findAll() { 
        List<Student> students=studentDao.findAll();
        System.out.println("查询到的数据的条数："+students.size());
        for (Student st:students
             ) { 
            System.out.println(st.toString());
        }
    }
    @Test
    public void add(){ 
        Student student=new Student();
        student.setId(4);
        student.setName("李名明");
        student.setAge(19);
        student.setGradeId(3);
        studentDao.add(student);
        findAll();
    }
    @Test
    public void delete(){ 
        studentDao.delete(4);
        findAll();
    }
    @Test
    public  void update(){ 
        Student student=new Student();
        student.setId(2);
        student.setName("王麻子");
        student.setAge(15);
        student.setGradeId(1);
        studentDao.update(student);
        findAll();
    }
    @Test
    public void fehefind(){ 
        List<Map> maps = studentDao.fuhefind();
        for (Map map:maps
             ) { 
            System.out.println(map);
        }
    }
}