Basic use of MongoDB and Java to the basic additions and deletions of MongoDB

Features of MongoDB

• MongoDB is a document storage database with flexible storage structure
• MongoDB supports complex query operations, support sequences
• MongoDB uses C + + development, can do distributed extension
• MongoDB is stored in bson format
• MongoDB supports JS engine, can write JS statement block

Installation and use

1. Run as administrator cmd.exe into the command line console and start the Mongod server,

mongod --dbpath F:\mongodb\data --logpath F:\mongodb\logs\a.log
启动mongo客户端:mongo

2. Start the server as a window service

Run Cmd.exe as administrator into the command line console

• Execute the Create MongoDB service command

  mongod --dbpath F:\mongodb\data --logpath F:\mongodb\logs\a.log --serviceName MongoDB --install

• Start and stop MongoDB services

  net start MongoDBnet stop MongoDB

• Delete MongoDB Service (stop service first)

  sc delete MongoDB

MongoDB Operations Command Library Operations (user space)

• Show DBS//See which libraries are available
• Use XXX//create using a library
• Db.dropdatabase ()//delete current Library

Collection Operations (table)

• Show collections//See which collections are in the current library
• Db.xxx.insert ()//Automatically create a collection when inserting records
• Db.xxx.drop ()//delete collection

Record Action (record)

• Db.xxx.insert ()//Insert Record

  db.emp.insert({"empno":1001,"ename":"tom"})db.dept.insert([{"dno":111,"dname":"ui"},{"dno":112,"dname":"h5"}])for(var i=1;i<100;i++){    db.dept.insert({"dno":i,"dname":"java"+i});};

• Db.xxx.find ()//enquiry Record

  db.emp.find()db.dept.find({"dno":50})db.dept.find({"dno":{$gt:90}})db.dept.find({"dname":/h/})

• Db.xxx.update ()//update record

  //整体更新db.dept.update({"dno":2},{"dname":"php"})//局部更新db.dept.update({"dno":3},{$set:{"dname":"h5"}})//更新多条记录,第三个false表示没有符合记录不插入;true表示插入。第四个参数true表示多行更新;false表示单行db.dept.update({"dno":{$lt:10}},{$set:{"dname":"JAVA"}},false,true)

• Db.xxx.remove ()//delete record

  db.emp.remove({})db.dept.remove({"dno":1})db.dept.remove({"dno":{$gt:50}})

Other operations

• Statistics

  //统计dept记录数量db.dept.count()//获取dname值，去重db.dept.distinct("dname")

• Sort

  //按dname降序排列db.dept.find().sort({"dname":-1})//按dname升序排列db.dept.find().sort({"dname":1})

• Page out

  //获取前5条记录db.dept.find().limit(5)//跳过5条再取5条(取6-10)db.dept.find().skip(5).limit(5)

• Index

  db.dept.ensureIndex({"dname":1})        db.dept.dropIndexes()db.dept.find({"dname":"java99999"}).explain("executionStats")

Java access MongoDB based on Mongo-java package basic access

API Introduction

- MongoClient  连接对象  Mongo- MongoDatabase 库对象   DB- MongoCollection 集合对象  DBCollection- MongoCursor 查询结果集对象 DBCoursor- Document 记录对象  DBObject

 Public classmongodbtest {@Test Public voidtest1 () {mongoclient m=NewMongoclient ("localhost", 27017); Mongoiterable<String> dbs = M.listdatabasenames ();//Querying the Database listMongocursor<string> iterator =Dbs.iterator ();  while(Iterator.hasnext ()) {System.out.println (Iterator.next ()); }    }    //Query All tests@Test Public voidtest2 () {mongoclient m=NewMongoclient ("localhost", 27017); Mongodatabase DBS= M.getdatabase ("java20");//Querying database Names        ///Query database table/JAVA20.JAVA20Mongocollection<document> collection = Dbs.getcollection ("Java20"); Mongocursor<Document> cusor = Collection.find (). iterator ();//Querying Data//Iterate with iterators         while(Cusor.hasnext ()) {Document Next=Cusor.next (); Object Object= Next.get ("User"); String name= next.getstring ("name"); String pwd= Next.getstring ("pwd"); System.out.println ("UserID" + Object + "Name:" + name + "| |:P assword:" +pwd); }    }        //Filter Query Test@Test Public voidtest3 () {mongoclient m=NewMongoclient ("localhost", 27017); Mongodatabase Database= M.getdatabase ("Java20"); Mongocollection<Document> collections = Database.getcollection ("Java20"); //Bson filter = filters.lt ("DNO", ten);//{"DNO": {$lt: ten}}Bson lt = filters.lt ("User", 10); Mongocursor<Document> documents =Collections.find (LT). iterator ();  while(Documents.hasnext ()) {Document D=Documents.next (); Object userid= D.get ("User"); Object name= D.get ("name"); Object pwd= D.get ("pwd"); System.out.println ("ID:" + userid + "name is:" + name + "Password is:" +pwd);    } m.close (); }    //Insert Test@Test Public voidtest4 () {mongoclient m=Newmongoclient (); Mongodatabase Database= M.getdatabase ("java20");//use a database of java20mongocollection<document> coll= database.getcollection ("emp");//Find the EMP table and create a table without an EMP tableDocument Doc=NewDocument (); Doc.put ("Eno", 1003); Doc.put ("Ename", "being"); Doc.put ("Salary", 5755);    Coll.insertone (DOC); }        //Local Updates@Test Public voidTest5 () {mongoclient m=NewMongoclient ("localhost", 27017); Mongodatabase Database= M.getdatabase ("java20");//Gets the library name of the current databasemongocollection<document> emp = database.getcollection ("emp");//Bson where= Filters.eq ("Eno", 1002);//Document Doc=NewDocument (); Doc.put ("Salary", 8356);//{"Salary": 4646}Document up=NewDocument (); Up.put ("$set", Doc);//{$set: {"Salary": 5657}}//updates are used hereEmp.updateone (where, up);    M.close (); }        //All Updates@Test Public voidTest6 () {mongoclient m=NewMongoclient ("localhost", 27017); Mongodatabase Database= M.getdatabase ("Java20"); Mongocollection<Document> emp = database.getcollection ("emp")); Bson eq= Filters.eq ("Eno", 1003); //System.out.println (eq); Filter{fieldname= ' Eno ', value=1003}Document doc=NewDocument (); Doc.put ("Salary", 500); //the replacement is used hereEmp.replaceone (EQ, doc);//All UpdatesM.close (); }}

Basic use of MongoDB and Java to the basic additions and deletions of MongoDB