MongoDB(六)java操作mongodb增删改查
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2022-04-21 11:09:20
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java操作mysql数据库的代码我们已经了如指掌了,增删改查,java对mongodb数据库也是类似的操作,先是数据库连接,再是进行操作。 首先我们进入进入admin数据库,然后建立自己的数据库testMongoDb,进入admin数据库后,就可以直接进入testMongoDb,因为用户可
java操作mysql数据库的代码我们已经了如指掌了,增删改查,java对mongodb数据库也是类似的操作,先是数据库连接,再是进行操作。
首先我们进入进入admin数据库,然后建立自己的数据库testMongoDb,进入admin数据库后,就可以直接进入testMongoDb,因为用户可以进入系统的数据库,就是超级管理员,use testMongoDb后,为该数据库设置用户名和密码,db.addUser('root','root'),这样我们在程序中连该数据库,并实现增删改查。
代码如下所示。
package com.mkyong.core; import java.net.UnknownHostException; import java.util.Date; import com.mongodb.BasicDBObject; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBCursor; import com.mongodb.Mongo; import com.mongodb.MongoException; /** * Java + MongoDB Hello world Example * */ public class App { public static void main(String[] args) { try { /**** Connect to MongoDB ****/ // Since 2.10.0, uses MongoClient //MongoClient mongo = new MongoClient("localhost", 27017); Mongo mongo = new Mongo("127.0.0.1",27017); /**** Get database ****/ // if database doesn't exists, MongoDB will create it for you DB db = mongo.getDB("testMongoDb"); //database username root and password root boolean ok = db.authenticate("root","root".toCharArray()); if(ok){ System.out.println("db connection success!"); }{ System.out.println("db connection fail !"); } /**** Get collection / table from 'testMongoDb' ****/ // if collection doesn't exists, MongoDB will create it for you DBCollection table = db.getCollection("user"); /**** Insert ****/ // create a document to store key and value BasicDBObject document = new BasicDBObject(); document.put("name", "mkyong"); document.put("age", 30); document.put("createdDate", new Date()); table.insert(document); /**** Find and display ****/ BasicDBObject searchQuery = new BasicDBObject(); searchQuery.put("name", "mkyong"); DBCursor cursor = table.find(searchQuery); while (cursor.hasNext()) { System.out.println(cursor.next()); } /**** Update ****/ // search document where name="mkyong" and update it with new values BasicDBObject query = new BasicDBObject(); query.put("name", "mkyong"); BasicDBObject newDocument = new BasicDBObject(); newDocument.put("name", "mkyong-updated"); BasicDBObject updateObj = new BasicDBObject(); updateObj.put("$set", newDocument); table.update(query, updateObj); /**** Find and display ****/ BasicDBObject searchQuery2 = new BasicDBObject().append("name", "mkyong-updated"); DBCursor cursor2 = table.find(searchQuery2); while (cursor2.hasNext()) { System.out.println(cursor2.next()); } /**** Done ****/ System.out.println("Done"); } catch (UnknownHostException e) { e.printStackTrace(); } catch (MongoException e) { e.printStackTrace(); } } } 控制台输入结果如下: db connection success! db connection fail ! { "_id" : { "$oid" : "544073c4d58dfa6e469555ba"} , "name" : "mkyong" , "age" : 30 , "createdDate" : { "$date" : "2014-10-17T01:41:24.479Z"}} { "_id" : { "$oid" : "543e154bd58d704982fd38f0"} , "name" : "mkyong-updated" , "age" : 30 , "createdDate" : { "$date" : "2014-10-15T06:33:47.321Z"}} { "_id" : { "$oid" : "5440719dd58d08a207605c8e"} , "name" : "mkyong-updated" , "age" : 30 , "createdDate" : { "$date" : "2014-10-17T01:32:13.922Z"}} { "_id" : { "$oid" : "544073c4d58dfa6e469555ba"} , "name" : "mkyong-updated" , "age" : 30 , "createdDate" : { "$date" : "2014-10-17T01:41:24.479Z"}}
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