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