Mongo实验
MongoDB数据库操作
Student:
{ “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;
cmd界面进入mongo命令
use mongodb_test
db.createCollection("Student")
db.Student.insertOne({name:'zhangsan',score:{English:69,Math:86,Computer:77}})
db.Student.insertOne({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()
(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.updateOne({name:”lisi”},{$set:{“score.Math”:NumberInt(95)}})
db.Student.find({name:”lisi”})
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)
代码:
package Mongo;
import com.mongodb.MongoClient;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoCursor;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import java.util.ArrayList;
import java.util.List;
public class MongoDBJDBC {
public static void main(String[] args) {
MongoCollection<Document> collection = getCollection("mongodb_test","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);
System.out.println("连接成功");
return collection;
}
public static void insert(MongoCollection<Document> collection){
Document document=new Document("name","scofield").append("score", new Document("English",45).append("Math", 89).append("Computer",100));
List<Document> documents=new ArrayList<Document>();
documents.add(document);
collection.insertMany(documents);
System.out.println("插入成功!");
}
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.out.println("查找失败");
System.err.println( e.getClass().getName() + ": " + e.getMessage() );
}
}
}
截图: