Article directory The following two tables are explainedSELECTDISTINCTWHEREAND ORINBETWEENwildcardLIkeORDER BYfunctioncity tableString functionsCommonly used function examples:concatsubstrtrimregionreplacegroup byhaving Aliassubqueryexiststable linkUse subqueries to implement multi-table queriescreate viewunion intersection valueNo intersection valuecaseThe difference between null and no value (... »
1. Download mysql8.0.26 (currently the latest version) https://dev.mysql.com/downloads/mysql/ 2. No login, just download 3. Unzip the compressed package to the directory where you usually install the software. 4. Configure environment variables after decompression [This computer]-[Right-click]-[Properties]-[Advanced system settings]-[Environment variables]-[Find the path in the system variables]-[... »
I. Introduction As an employee of an e-commerce company, I deeply understand the severe challenges of ensuring the normal use of services under heavy system pressure and high concurrency. During Double 11, our database service was severely strained due to the surge in usage, and the pressure was extremely high. There were even failures such as missed transactions and dirty data. Even if we have a ... »
Today I will continue to introduce you to MySQL-related knowledge. The main content of this article is the basic principles of MySQL Cluster. 1. MySQL Cluster Principle MySQL Cluster is a common technology for MySQL clusters and is suitable for high redundancy and practical versions in distributed computing environments. In MySQL Cluster, the structure and function of the database are split into t... »
1. Background The leader asked to use kettle,Synchronize sqlsever data to mysql, so I thought that the kettle tool can also configure incremental synchronization and scheduled synchronization. As a result, the connection took a long time. I am a newbie and not very familiar with the operation. Hahaha, don’t be dissatisfied, masters, just record the process. Don’t mind your level when writing an ar... »
Source code acquisition: Download from “Resources” on the blog homepage! 1. Project operationEnvironment configuration: Jdk1.8 + Tomcat8.5 + mysql + Eclispe (IntelliJ IDEA, Eclispe, MyEclispe, Sts support) Project technology: JSP + Servlert + html+ css + JavaScript + JQuery + Ajax, etc.; Personal Center Controller: /** * Personal Center Controller */ @Controller public cl... »
DataSourceTransactionManager Summary 1.Spring framework configuration transaction1.1 Schema-based automatic proxy1.2 Use @transactional annotation 2.SpringBoot framework configuration transaction2.1@Transactional annotation2.1.1SpringBoot automatically assembles the transaction manager 2.2SpringBoot multiple data source configuration 2.2.1 Specify a transaction manager for the data source2.2.2 Spe... »
Source code acquisition: Download from “Resources” on the blog homepage! 1. Brief description of the project Function: User’s email registration, verification code verification and user login. There is no need to register an account, and you can also upload temporary files that meet the conditions, but they are only valid for 4 hours. File management, upload, download, rename, delete, ... »
1. What is MybatisX? MybatisX is a rapid development plug-in based on IDEA, which is easy to usemybatisas well asmybatis-plusSimplify tedious repetitive operations at the beginning and increase development speed. 2. Benefits of using MybatisX Save a lot of persistence layer code development time Powerful functions provide various supports for business writing ... »
References: “Explain | Do you really know how to use this great sword of index optimization?” 》 “Completely understand MySQL’s explanation with one picture” “MySQL Performance Optimization Artifact Explain Usage Analysis” “MySQL Index Application: The correct approach to index creation and the best guide to using indexes!” 》 “MySQL index ... »
