MOGODB Connection Test

– $in

db.Student.find({"_id":{"$in":[1001,1002,1]}})

– $or

db.Student.find({"$or":[{"_id":99},{"pageViews":2}]})

–and and OR

db.Student.find({"pageViews":2,"$or":[{"_id":99}]})

Cursor control

for(i=0;i<10;i++){    db.Student.insert({"_id":i});}var cursor=db.Student.find();cursor.forEach(function(x){    print(x);});

– Paged Query

db.Student.find().limit(3)     db.Student.find().limit(3).skip(3)

– Sorting

db.Student.find().sort({"_id":-1})      --1为升序，-1为降序db.Student.find().sort({"_id":-1,"pageView":1})  --前面如果相同就按后面pageView的升序来排序

DBHelper:

 PackageCom.yc.link;ImportJava.net.UnknownHostException;ImportCom.mongodb.DB;ImportCom.mongodb.DBCollection;ImportCom.mongodb.Mongo;ImportCom.mongodb.MongoException; Public  class dbhelper {        Private StaticMongo mongo=NULL;PrivateDB db=NULL;Static{Try{mongo=NewMongo (Mypro.getinstance (). GetProperty ("IP"), Integer.parseint (Mypro.getinstance (). GetProperty ("Port"))); }Catch(NumberFormatException e)            {E.printstacktrace (); }Catch(Unknownhostexception e)            {E.printstacktrace (); }Catch(Mongoexception e) {//TODO auto-generated catch blockE.printstacktrace (); }        } Public Boolean Getdb(String dbname,string name,string pwd) {Mongo.getdb (dbName);if(name!=NULL&&!"". Equals (name) &&pwd!=NULL&&!"". Equals (PWD) {if(Db.authenticate (name, Pwd.tochararray ())) {return true; }Else{return false; }            }Else{//See if a user name and password are given in the configuration fileString uname=mypro.getinstance (). GetProperty ("Uname"); String pwds=mypro.getinstance (). GetProperty ("Password");if(name!=NULL&&!"". Equals (name) &&pwd!=NULL&&!"". Equals (PWD) {if(Db.authenticate (name, Pwd.tochararray ())) {return true; }Else{return false; }            }        }return true;}/** * Close link * */ Public void CloseAll(Mongo Mongo) {if(mongo!=NULL) {mongo.close (); }}/** * Gets the specified collection * CollectionName the collection to link * dbname the database where the collection resides * The username of the linked data * The password of the linked database * */ PublicDbcollectiongetdbcollection(String collectionname,string DbName) {dbcollection dbcollection=NULL;if(Getdb (DbName,NULL,NULL)) {Db.requeststart ();if(collectionname==NULL){//If empty, the flush configuration file is loadedCollectionname=mypro.getinstance (). GetProperty (CollectionName);    } dbcollection= db.getcollection (CollectionName); }Else{Throw NewRuntimeException ("Database connection failed ..."); }returnDbcollection;} PublicDbcollectiongetdbcollection(String collectionname,string dbname,string name,string password) {dbcollection dbcollection=NULL;if(Getdb (Dbname,name,password)) {Db.requeststart ();if(collectionname==NULL){//If empty, the flush configuration file is loadedCollectionname=mypro.getinstance (). GetProperty (CollectionName);    } dbcollection= db.getcollection (CollectionName); }Else{Throw NewRuntimeException ("Database connection failed ..."); }returnDbcollection;}}

Mypro: Single case

 PackageCom.yc.link;ImportJava.io.IOException;ImportJava.io.InputStream;ImportJava.util.Properties; Public  class mypro extends Properties {        Private StaticMypro instance=NewMypro ();Private Mypro() {InputStream Is=mypro.class.getresourceasstream ("/db.properties");Try{ This. Load (IS); }Catch(IOException e)            {E.printstacktrace (); }finally{if(is!=NULL){Try{Is.close (); }Catch(IOException e)                    {E.printstacktrace (); }                }            }        } Public StaticMyprogetinstance(){returnInstance }}

package com.yc.link;publicclass Test {    publicstaticvoidmain(String[] args) {            DBHelper db=new DBHelper();            System.out.println(db);    }}

Db.properties

ip=127.0.0.1port=27017dbName=uname=password=collectionName=

DBHelper should be more in the encapsulation of some common methods, you can go to the internet slowly collect

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MOGODB Connection Test