• Common crud operation statements of mongodb


    catalogue Create data (create) Update data (update) Delete Read data (read) For the back-end God (Xiaobai), the daily work is crud, plus control + C and control + V. As a great God (Xiaobai), how can you not understand crud? Compared with cumbersome SQL statements, mongodb crud is very simple and modern. Create data (create) […]

  • Precautions and simple use of mongodb ORM framework


    catalogue Ⅰ. brief introduction Ⅱ. matters needing attention Ⅲ. usage method Ⅳ. course First of all, spring comes with mongodb‘s ORM, spring data mongodb, but this framework is very difficult to use. The most annoying thing is that each document has to bring one_ The class field takes up a lot of space because it […]

  • How does mongodb update the data of multi-level documents


    catalogue Nested array update Update properties of subordinate documents Attribute addition and removal summary Nested array update Take the following data (dataset name is author) as an example: {Name: ‘code farmers on the island’, documents: [‘introduction and actual combat of fluent’, ‘high performance mysql’, ‘mongodb professional North’]} We need to change mongodb professional North pointing […]

  • Analyze the key features, differences and advantages of mongodb and mysql


    catalogue What is MySQL? What is mongodb? Differences between mongodb and MySQL Data mode and capacity Performance and speed Security Characteristics of transactions: atomicity, consistency, isolation and persistence query Mongodb vs. MySQL: under what conditions conclusion Mongodb and MySQL are both good databases with excellent performance. However, their success depends on the application scenario. First, […]

  • Explain the conditional query and sorting of mongodb in detail


    catalogue Find method Condition combination Comparison operator In query Limit the number of returned results and skip data sort summary Find method The basic format of query is dB collection. Find ({condition}), where the condition is optional, similar to the where condition of MySQL. Examples are as follows: //Find all documents db.collection.find({}); //Find documents with […]

  • Implementation steps of integrating mongodb with springboot


    catalogue 1、 Technical introduction 1. What is mongodb? 2、 Use steps 1. Import Maven Library 2. Specific use examples 3. Configuration file 4. Unit test summary 1、 Technical introduction 1. What is mongodb? Mongodb (from the English word “humongous”, which means “huge” in Chinese) is an open source database that can be applied to enterprises […]

  • Analysis of security authentication of mongodb


    catalogue 1、 User and role permissions of mongodb 1.1. View all built-in roles 1.2. Common built-in roles 2、 Single instance environment 2.1. Create user 2.2. Server start authentication 2.3 client login authentication 3、 Replica set environment 3.1. Add management account 3.2. Create a key file for replica set authentication 3.3. Modify the configuration file and […]

  • Mongodb installs, uses and implements Python operation database


    catalogue 1、 Introduction to mongodb 2、 Install mongodb 3、 Using mongodb 1. Insert data 2. Find data 3. Update data 4. Delete data 5. Conditional operator 6. Mongodb limit and skip method 7. Mongodb sorting 8. Mongodb index 8. Mongodb aggregation IV. Python operation mongodb 1、 Introduction to mongodb Mongodb is a database based on […]

  • Handling method of abnormal restart of Mongo service


    discover problems Now the company’s servers are often powered off, so it is necessary to restart all services regularly. However, among these redis, mysql, Mongo and other services, Mongo often fails to restart. According to previous experience and information posted on the network, here is a summary; First of all, the services installed here are […]

  • Introduction and format analysis of oplog in mongodb


    catalogue 1. Basic concepts 2. Default storage size of oplog 3. You may need a larger workload of oplog 4. Oplog status 5. Oplog format 6. Correspondence between cud operation and oplog Delete operation Update operation Summary summary 1. Basic concepts Oplog uses a fixed size set to record the operation logs of all modification […]

  • Sample code of commonly used mongodb query statements


    catalogue background method Query example Example 1 Example 2 Example 3 Example 4 Last words background Recently, I have made several rule logic. Mongo query is often used, which is to query the transaction information, run the established rules to screen out the trading merchants, use the aggregation pipeline for statistics and take out the […]

  • Detailed explanation of mongodb installation and startup


    Installation and startup of mongodb Step 1 [download installation package] 1. Go to mongodb’s official website to download the corresponding installation package( the appropriate version to download2. If there is a network, directly use the command to download (WGet) Step 2 【 decompress the compressed package 】 tar zxvf mongodb-linux-i686-1.8.0.tgzIt’s best to change the name […]