• JS advanced learning notes – constantly updating


    Classes and objects in ES6 Create class grammar // 1. Create class class Star{ constructor(uname,age){ this.uname = uname; this.age = age; } } // 2. Create new object with class Var LDH = new star (‘andy Lau ‘, 18) Var ZXY = new star (‘jacky Cheung ‘, 20) console. Log (LDH. Uname) // print an […]

  • App optimization and standings advanced part 1 [Mui + flask + mongodb]


    Article catalogue 1、 Foreword 2、 Demand 1 & 2: add registered classes and select [drop-down list] 2.1 basic HTML style 2.2. JS monitoring 2.3. Modify flash backend 2.4. Optimize the display of personal homepage 3、 Demand 3: increase friendliness and add segments to the personal scoreboard 4、 For demand four About the author: Hello, I’m […]

  • Springboot integrates mongodb subset operations


    1、 New entity class 1. New comment class package com.hq.mongodb.entity; import lombok.AllArgsConstructor; import lombok.Data; import lombok.NoArgsConstructor; import lombok.experimental.Accessors; import java.util.Date; import java.util.List; @Data @AllArgsConstructor @NoArgsConstructor @Accessors(chain = true) public class Comment { /** * id */ private Integer id; /** *Comment content */ private String content; /** *Comment level */ private String grage; /** *User […]

  • Improvement of login module based on [Mui + flask + mongodb + hbuilderx]


    Welcome to pay attention 🍋App development from 0 to 1make joint efforts 1、 Catalogue Article catalogue 1、 Catalogue 2、 Foreword 3、 Today, focus on the modification of personal information 3.1. Precautions: 4、 Back end (primary): 4.1. Mongodb is explained with Python operation: 5、 Front end (minor problems): an account of happenings after the event being […]

  • [go language practice] (7) Im instant chat demo based on websocket + mongodb


    Article catalogue Write in front 1. Principle of websocket 2. Specific process 2.1 definition type 2.2 connection 2.2.1 server listening connection 2.2.2 server listening disconnection 2.2.3 user connection server 2.3 writing 2.3.1 definition type 2.3.2 reading data 2.3.3 accept message 2.3.3 get historical messages 2.4 reading 2.5 insertion and query 2.5.1 insert data 2.5.2 query […]

  • 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) […]

  • Mongodb step by step development (windows10) IV. create the first database


    Mongodb step by step development (windows10) 4、 Create the first database 1. Basic syntax for mongodb to create database use DATABASE_NAME 2. Create the first database database1Open mongo.com in administrator mode Exe client. When you enter the mongodb background, it will link to the test database by defaultEnter the show DBS command to display the […]

  • 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 […]

  • Ha scheme of mongodb


    Relational database Common relational databases include mysql, Oracle, DB2 and SQL serverThe non relational database has mongodb Relational database can be understood as a database created by relying on one model. Because it is based on the data model, we can easily do complex query operations between multiple tables through SQL statements Relational database is […]

  • 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 […]