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() );
}
}
}
