MongoDB

If the type writes an error, it can be modified in the command line in the following way.Db.jobtracker_data.find ({' collect_time ': {$type: 2}}). ForEach (function (x) { x.collect_time = parseint (x.collect _time); Db.jobtracker_data.save (x);

Insert Document:Db.foo.insert ({"Key": "Value"});Inserting a data using insert will automatically add _id to the document if no _id is in the document.Batchinsert (array) BULK INSERT, accept a document array to do parameters.Use BULK Insert maximum

A document is a basic unit of data in MongoDB, a row in a type-relational database, and each document has a key _id that is unique to thekey value. collections can be seen as tables that have dynamic schemas.MongoDB An instance can have multiple

Capped Collection Fixed Set Simple Introduction Capped collections is a well-performing, fixed-size collection that performs used (aging-out) processing with LRU (Least recently age-out Least recently used) rules and insertion order, automatically

1, update () command basic use, (by default, just update a query to meet the criteria of the information does not exist by default, not added)Note that the simple use of Db.user.update ({"Name": "User6"},{name: "user111"},0,1) will replace records

[1] Creating Directorys and filesCreate a configuration file and a directory path for MongoDB log Output ( logpath): First, you will manually create a new Windows service:  Create the address of the log file:MD "C:\Program Files\mongodb\log" at

MongoDB is a popular NoSQL database, it is stored in the form of document-type storage, not key-value.  There are three triples in MongoDB: A database, a collection, a document, where "set" is the "table" in the corresponding relational database,

Flush () is the force output of the buffer data (note not to be confused with Frush () refresh). mainly used in Io, that is, to empty the buffer data, generally in the read and write stream (stream), the data is read into the memory, and then write

MongoDB occupies a much larger disk space than MySQL, can understand the document data such as JSON format, there are many redundant data, but the space consumption is not normal, even the traditional database three or four times times, does not fit

1. Insert operationuser = {"username": "LCQ", "Sex": "Man"}db.user.insert (user)2. Updatevar LCQ = Db.user.findOne ({"username": "LCQ"}}lcq.address = {"Province": "Shandong", "Location": "Zoupin"}lcq.haha = " Hehhehe "Db.user.update ({" username ":"

The previous version of the configuration file in a few words, now the MongoDB 3.0 kernel Niaoqianghuanpao, the efficiency is greatly improved.Excited.... Today I'm ready to deploy to the server.To download the installation, the configuration file

Emergency out of a bad, but can not continue to write, write less, first put Shard key and hash of some small concepts continue to write.Shard KeysThe most important thing about MongoDB's sharding is Shard key. Shard with Shard Key, and divide and

The previous article introduced HTTP/2, a brief introduction to MongoDB 3.0, released March 3.What ' s new in MongoDB 3.0? New Storage Engine WiredtigerThe storage engine for MongoDB 3.0 is plug-in and defaults to the new Wiredtiger. Wiredtiger

MongoDB is installed using the Yum command of CentOS, the entire installation process is as follows:1. RunningYum Info Mongo-10genSee if there is a MongoDB source, such as skip to step 3rd.2. RunningVim/etc/yum.repos.d/10gen.repoEnter the following

Recently, using MongoDB, it is found that MONGO's definition of field type is not very strict, it relies entirely on the type of incoming data, and the addition of PHP is a weak type of language, so there will inevitably be some errors. If the

Someone on the Quora asked: What is the organizational structure inside the MongoDB data file ? Then 10gen engineer Jared Rosoff came out to do a short answer. Each database has its own separate files. If you turn on the DIRECTORYPERDB option, the

MongoDB Common Command Scripting-automated OPS writes the MONGODB commands commonly used in operations into shell scripts, greatly facilitates maintenance1 Modifying the settings of a replica set#!/bin/bash#mongodb Enter the client and enter

MongoDB is a powerful, flexible, and easy-to-scale universal database.Design features:1. Easy to useMongoDB is a document-oriented (document-oriented) database, not a relational database.2. Easy to expandThe design of MongoDB is scaled out

After the successful start of MongoDB, and then open a command line window input MONGO, you can do some of the database operations.Enter help to see the basic Operations Command:Show DBS: Display Database listShow Collections: Displays a collection

Create an index using the Ensureindex method, for the same collection, the same index needs to be created once, and repeated creation is futile.The index of a key accelerates the query for that key, however, it may not help for other queries, even