mongoDB练习

MongoDB数据库操作

Student文档如下:

{

“name”: “zhangsan”,

“score”: {

“English”: 69,

“Math”: 86,

“Computer”: 77

}

}

{

“name”: “lisi”,

“score”: {

“English”: 55,

“Math”: 100,

“Computer”: 88

}

}

 

1.根据上面给出的文档，完成如下操作：

（1）用MongoDB Shell设计出student集合；

use School

db.createCollection('student') db.student.insert({name:'zhangsan',score:{English:69,Math:86,Computer:77}}) db.student.insert({name:'lisi',score:{English:55,Math:100,Computer:88}})

 

（2）用find()方法输出两个学生的信息；

db.student.find()

db.student.find().pretty()

 

 

（3）用find()方法查询zhangsan的所有成绩(只显示score列)；

db.student.find({name:'zhangsan'},{'score':1})

 

 

（4）修改lisi的Math成绩，改为95。

db.student.update({name:'lisi'},{$set:{'score.Math':95}})

 

 

2.根据上面已经设计出的Student集合，用MongoDB的Java客户端编程，实现如下操作：

（1）添加数据：English:45 Math:89  Computer:100

与上述数据对应的文档形式如下：

{

“name”: “scofield”,

“score”: {

“English”: 45,

“Math”: 89,

“Computer”: 100

}

}

   

（2）获取scofield的所有成绩成绩信息(只显示score列)

package org.example;

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

import org.bson.Document;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.model.Filters;

public class mongo {

    public static void main(String[] args) {
        MongoCollection<Document> collection = getCollection("School","student");
        insert(collection);
        find(collection);
    }

    public static MongoCollection<Document> getCollection(String dbname,String collectionname){
        MongoClient  mongoClient=new MongoClient("localhost",27017);
        MongoDatabase mongoDatabase = mongoClient.getDatabase(dbname);
        MongoCollection<Document> collection = mongoDatabase.getCollection(collectionname);
        return collection;
    }
    public static void insert(MongoCollection<Document> collection){
        try{
            Document doc=new Document("name","scofield").append("score", new Document("English",45).append("Math",89).append("Computer",100));
            collection.insertOne(doc);
            System.out.println("插入成功");
        }catch(Exception e){
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }
    }
    public static void find(MongoCollection<Document> collection){
        try{
            MongoCursor<Document>  cursor= collection.find(new Document("name","scofield")).projection(new Document("score",1)).iterator();
            while(cursor.hasNext()){
                System.out.println(cursor.next().toJson());
            }
        }catch(Exception e){
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }
    }
}