Common commands of MongoDB (CRUD)
1, Database operation
1) Select and create database syntax:
use database name
The rule of the use command is to switch if the corresponding database exists, and create if it does not exist
2) Deletion of database
db.dropDatabase()
3) View databases with permissions
show dbs or show databases
Note: when you use the use com ...
Posted on Sun, 05 Dec 2021 02:17:05 -0500 by SwiftlyTilting
mongoDB replica set and partitioned cluster
mongoDb replica set
It mainly provides two functions
1. When data is written to the Primary node, copy the data to another replica node
2. When the primary node fails, a new replacement node is automatically selected
Typical replica set structure
A typical replication set consists of three or more nodes with voting rights. ...
Posted on Wed, 01 Dec 2021 06:28:12 -0500 by skippy111
Blind ditch low ratio? No, no, no, it's mango's pen. Today, learn about the distributed file storage database MongoDB.
As usual, the figure above first. In the last NOSQL article, a big man said that he would learn all the databases of the first figure. Today, he specially posted only one small figure. One is enough!
preface
Mongo does not mean Mango, but comes from the word Humongous.
MongoDB is a NoSQL database based on distributed file storage. W ...
Posted on Mon, 29 Nov 2021 08:24:23 -0500 by cs-web
Summary of MongoDB learning notes (including errors, problems, techniques)
Environmental Science
OS: Ubuntu20.04
MongoDB: v5.0.2
Introduction to MongoDB
MongoDB is an open source document database that provides high performance, high availability, and automatic scaling to provide scalable high performance data storage solutions for WEB applications.
MongoDB is a product between relational and non-relational datab ...
Posted on Fri, 26 Nov 2021 15:12:50 -0500 by Cugel
CentOS 7.9 MongoDB installation and use
CentOS 7.9 MongoDB installation and use
1, Software download and installation
Note: CentOS versions include RedHat / CentOS 7.0 and RedHat / CentOS 7.2 s390x. It is recommended to download software installation packages consistent with the CPU architecture of the operating system to ensure compatibility and high performance. Enter arch ...
Posted on Thu, 11 Nov 2021 21:19:57 -0500 by invinate
MongoDB Map Reduce aggregation
MongoDB Map Reduce
MAP REDUCE is a computing model, which simply means that a large number of work (data) are decomposed (MAP) and executed, and then the results are combined into the final result (REDUCE).
The map reduce provided by MongoDB is very flexible and practical for large-scale data analysis.
MapReduce command
The following is t ...
Posted on Thu, 28 Oct 2021 02:25:17 -0400 by rekha
Mongodb -- addition, deletion, modification and query of Java
1: jar packages to be referenced:
<!-- mongodb Link package -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
<version>2.3.4.RELEASE</version>
</dependency>
2: This ...
Posted on Sun, 26 Sep 2021 03:20:45 -0400 by Worqy
Java MongoDB Save Pictures
This article describes how to save a picture file to MongoDB using the GridFS API.The GridFS API can also save other binary files, such as video and music files.
1. Save pictures
The following code uses the photo namespace, and the new filename saves the picture to MongoDB.
String newFileName = "mkyong-java-image";
File imageFile = new ...
Posted on Mon, 29 Jun 2020 12:24:51 -0400 by NewPHP_Coder
Build Mongodb cluster in detail under centos7
1, Mongodb cluster (no SQL Library) cluster construction
1. For the topology of Mongo cluster, let's have a brief understanding2. Install mongodb to node1, 2, and 3 nodes (the following operations should be performed on node1, 2, and 3 nodes, xshell is recommended)
(1) Configure mongo's yum source
Com ...
Posted on Mon, 29 Jun 2020 03:12:11 -0400 by madhukar_garg
mongoDB and pymongo learning
Contents of this article
The foregoing
install
linux Installation
docker container deployment
Windows setup
use
GUI viewer
Differences between mongoDB and relational database
mongoDB basic syntax
pymongo module usage
The foregoing
mongoDB should be a non relational database according to the ...
Posted on Fri, 26 Jun 2020 04:24:11 -0400 by vertmonkee