mongodb插入文档和检索文档

2022/6/3 2:20:22

本文主要是介绍mongodb插入文档和检索文档,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

import com.mongodb.client.*;
import com.mongodb.client.MongoClient;
import com.mongodb.client.model.Filters;
import com.mongodb.client.result.DeleteResult;
import com.mongodb.client.result.UpdateResult;
import org.bson.Document;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Consumer;

import static com.mongodb.client.model.Accumulators.sum;
import static com.mongodb.client.model.Aggregates.group;
import static com.mongodb.client.model.Aggregates.match;
import static com.mongodb.client.model.Aggregates.project;
import static com.mongodb.client.model.Filters.and;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Filters.exists;
import static com.mongodb.client.model.Filters.gt;
import static com.mongodb.client.model.Filters.gte;
import static com.mongodb.client.model.Filters.lt;
import static com.mongodb.client.model.Filters.lte;
import static com.mongodb.client.model.Projections.excludeId;
import static com.mongodb.client.model.Sorts.descending;
import static com.mongodb.client.model.Updates.inc;
import static com.mongodb.client.model.Updates.set;
import static java.util.Arrays.asList;
import static java.util.Collections.singletonList;

public class MyMongodbTest {

    public static void main(String[] args) throws Exception{
        try{
            // 连接到 mongodb 服务
//            MongoClient mongoClient = new MongoClient("localhost", 27017);
            MongoClient mongoClient = MongoClients.create();

            // 连接到数据库
            MongoDatabase mongoDatabase = mongoClient.getDatabase("mycol");
            System.out.println("Connect to database successfully");

            //不能重复创建
//            mongoDatabase.createCollection("test");
//            System.out.println("集合创建成功");

            MongoCollection<Document> collection = mongoDatabase.getCollection("test");
            System.out.println("集合 test 选择成功");

            //插入文档
            /**
             * 1. 创建文档 org.bson.Document 参数为key-value的格式
             * 2. 创建文档集合List<Document>
             * 3. 将文档集合插入数据库集合中 mongoCollection.insertMany(List<Document>) 插入单个文档可以用 mongoCollection.insertOne(Document)
             * */
            Document document = new Document("title", "MongoDB001").
                    append("description", "database").
                    append("likes", 100).
                    append("by", "Fly");
            List<Document> documents = new ArrayList<Document>();
            documents.add(document);
            collection.insertMany(documents);
            System.out.println("文档插入成功");

            //检索所有文档
            /**
             * 1. 获取迭代器FindIterable<Document>
             * 2. 获取游标MongoCursor<Document>
             * 3. 通过游标遍历检索出的文档集合
             * */
            FindIterable<Document> findIterable = collection.find();
            MongoCursor<Document> mongoCursor = findIterable.iterator();
            while(mongoCursor.hasNext()){
                System.out.println(mongoCursor.next());
            }


            //更新文档   将文档中likes=100的文档修改为likes=200
            collection.updateMany(Filters.eq("likes", 100), new Document("$set",new Document("likes",200)));
            //检索查看结果
            FindIterable<Document> findIterableUp = collection.find();
            MongoCursor<Document> mongoCursorUp = findIterableUp.iterator();
            while(mongoCursorUp.hasNext()){
                System.out.println(mongoCursorUp.next());
            }



        }catch(Exception e){
            System.err.println( e.getClass().getName() + ": " + e.getMessage() );
        }

    }

}

 



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