MongoDB

Because the new Windows 10 computer, you need to reinstall all the software on the new computer, including MongoDBdownload file : Start with the latest version of MongoDB installer on the official website of MongoDB, https://www.mongodb.com/, scroll

ObjectivePersonal understanding, a primary function of a replica set is when the master library fails, and one of the salve from the library is elected to become the new master. The frame diagram is as follows:Among them, the electors do not

There are two types of MongoDB references: Manual reference (Manual References) DBRefs DBRefs vs Manual ReferenceConsider a scenario in which we store different addresses (address, Office address, email address, etc.) in different

The Mongostat is a mongodb-brought tool that detects the running state of MongoDB.test:test/node-131/# Mongostat--helpUsage:Mongostat Monitor basic MongoDB Server statistics.See http://docs.mongodb.org/manual/reference/program/mongostat/for more

Document deletion Command Operation db.collection.deleteOne() Delete a single document that matches a specified filter, even if multiple documents may match the specified filter.

ExampleThe following mapping is an example of the following document:{ _id:ObjectId("509a8fb2f3f4948bd2f983a0"), user_id:"abc123", age:55, status:'A'}Create or Altercreate table or collectionCREATETABLE people (

First, the basicMongoDB does not need to explicitly create a database like a relational database, and can be created directly using the USE statement:> use fooInsert a document into the collection using the Insert method:> db.blog. Insert

Took a week to finally fix, across the various pits, finally debugging success, recorded as follows:1. First build the Douban crawler project in cmd with command lineScrapy Startproject Douban2, I use the pycharm, after importing the project,1)

MongoDB is also a database, like MySQL, there are servers, databases, tables, records concepts. You can also use command operations in the terminal.1. Connect MongoDBMONGO 127.0.0.1:270172. Show all databasesShow DBS;3. Using the DatabaseUse test;4,

Gridfs is a mechanism for storing a binary file in Mongodb. Gridfs is used to store and restore files that exceed the 16M(BSON file limit) ( e.g. pictures, audio, video, etc.) ). There are several reasons for using Gridfs :1 using Gridfs to

MongoDB default is not authentication, default no account, as long as the service can be connected to the database for a variety of operations,MongoDB believes that the best way to security is in a trusted environment to run it, Ensure that the

1 Downloadshttps://fastdl.mongodb.org/linux/mongodb-linux-x86_64-3.0.6.tgz2 unzip and copy to/usr/local/mongodbtar -zxvf mon*cp mongodb-linux-x86_64-3.0.6 /usr/local/mongo3 Configuring Environment Variables/etc/profilesudo 4 Create a new data

IntroducedThis article describes the steps to install node. JS in a Linux environment, followed by the installation of MongoDB.In addition, recommend me another article in the windows of MongoDB installation and configuration, first under Windows

Download MongoDB, this is for download MSI file installation, After the download is complete, double-click the file installation, install the installation path Create an empty folder to hold the database files Go to the Bin directory in the

MongoDB provides a 64-bit installation package for each Linux distribution, and you can download the installation package on the website.: https://www.mongodb.com/download-center#community Download the installation package and unzip the  tgz (The

The MongoDB replica set is a master-slave cluster with failover. is the evolution from the existing master-slave mode, which increases automatic failover and node member auto-recovery.There is no fixed primary node in the MongoDB replica set mode,

MongoDB Update character manipulationZhang Ying published in 2014-07-23Category list: NoSQLTags: $inc, $rename, $set, $unset, MongoDB, Multi, update, UpsertThe following commonly used update operation, with the mongodb2.6.3 version of the test, the

A single-page application based on Vue, Vuex, Express, MongoDB, including the front and back end, the frontend is mainly using Vue, the backend is node's express, the database is used MongoDB1. Download and usegit clone

The two days of contact with the MongoDB database, found and MySQL database is still very different, while the configuration before use looks a bit complicated, stepped on a lot of pits, in fact, as long as a step by step to understand, not

Introduction to MongoDb indexes and mongodb Indexes MongoDb Index 1. _ Id index: Default Index 2. single-Key Index: for example, a record: {x: 1, y: 2, z: 3}, statement db. collection. ensureIndex ({x: 1}) indicates creating an ascending index for