MongoDB

MongoDB Federated Query2012-04-15 16:32:44|  Category: MongoDB | Tags:mongodb mongodb Federated Query | Report | Font size Big medium small subscription 1. Simple manual correlationFirst, the results are queried and put into a variable,

Read the premise: the background of the code is this ID other posts: IP library Query The format is as follows: Begin End Provinces 18533376,18534399, Inner Mongolia Autonomous Region, Holonbuyr Simple code: public static iplocation getlocation (

var Query,b1,b2:tbson;   Buf:tbsonbuffer; Code:tbsoncodewscope; Begin if Dbman=nil then dbman:=tdbmanage.create;Buf:=tbsonbuffer.   Create;   Buf.startobject (' group '); Buf.append (' ns ', ' TESTC ');Buf.startobject (' key ');   Buf.append (' name

1. InstallationGo to the official website to download the version, MongoDB is divided into two versions: Windows and Linux.1.1 Windows installation is simpleFirst: Download a Windows compact package or Setup program.Then: in your disk character

Operation Steps I'm not refining anymore.Project can run, tested, first on the configuration, another article on the code, to the source package please leave the mailboxProject structurePom.xml4.0.0testspringmvc_mongodbwar0.0.1-snapshot

1,yum dependenciesCentos,rhel Fedora:$ sudo yum install git gcc automake autoconf libtoolDebian:$ sudo apt-get install git gcc automake autoconf libtoolFreebsd:$ Su-c ' pkg install git gcc automake autoconf libtool '2,fetch Sources and Buildgit

The role of distributed locksIn general, the function of a lock is to solve the problem that arises from the competition between different execution flows for the same resource. The function of distributed lock is to solve the problem of the

Based on MongoDB 2.6GeoJSON format{"type": "Point", "coordinates": [Lon (longitude), lat (latitude)]}Test dataDb.point.test.insert ({"Address": "Nanjing Lukou International Airport", "Loc": {"type": "Point", "coordinates": [118.783799,31.979234]}})

1. List all databases>show DBS2. Using the database>use Memo3. List the collections of the current database>show Collections4. Displaying data currently in Operation>db5. List Users>show Users6. New Database and data collection>db>show DBS If you

1,MONGODB introduction;MongoDB is a high-performance, open-source, modeless document-based database that is a popular one in the current NoSQL database. It can be used in many scenarios to replace the traditional relational database or key/value

Go to MongoDB Download Center:http://www.mongodb.org/downloadsWe recommend using these binary distributions (binary version is officially recommended!) According to your actual system environment, download the required files, mine is the Linux 64-

NoSQL (not only SQL)Why use NoSQLHigh concurrency for database read and writeEfficient storage and access to massive amounts of dataHigh scalability and high availability for databasesThe weakness of NoSQLDatabase Transactional Consistency

MONGODB CREATE Index > Db.foo.ensureIndex ({"X": 1, "Y":-1}) Use Ensureindex to create indexes, 1 for ascending, 1 for reverseTip: Query to return more than half of the results in the collection, but there is no need to create an index,

The Replica Setsmongodb supports failover and redundancy across multiple machines through asynchronous replication. At the same time in multiple machines, only one is used for write operations. It is for this reason that MongoDB provides the

for (Var i=0;iDb.user.insert ({name: "User" +i,age:i})} Add so much dataDb.user.find ({name: "user100"}) did not add an index to scan all dataDb.user.find ({name: "user100"}). Explain () can view information about using the index, such as the number

mongodb syntax MySQL syntax db.test.find ({'name':'Foobar'}) Select * fromTestwhereName='Foobar'Db.test.find () Select * fromTest Db.test.find ({'ID':Ten}).Count() Select Count(*) fromTestwhereId=Tendb.test.find (). Skip (Ten). Limit ( -) Select *

1 in-Shell for loop cleanup Remove the data by connecting MONGO each time echo "Begin ..." >>/root/time.log;echo $ (date +%y-%m-%d-%h:%m:%s) >>/root/time.log;for (i=1;i>/root/tickets.logdoneecho $ (date +%y-%m-%d-%h:%m:%s) >>/root/time.log; echo

MongoDB Basics1. DocumentationA document is a basic unit of data in MongoDB, similar to a row in a relational database management system.A document is an ordered set of key-value pairs. Typically contains one or more key-value pairs.For

First step: Open cmd, run Mongo.exeStep two: Referencing the database that needs to be loadedUse database name//If the database name does not exist, MongoDB will automatically establish the databaseStep Three: Assign a value to create a Document

There's no 1:key inside. , and then I would prefer to handle it as a custom symbol for _DOT_.2: Multi-use bulk operation, grammar forget to check it, in my needs I need to traverse a collection time to find that a variable is not true when the link