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The data source module for Mybatis is located inOrg.apache.ibatis.datasource. Common data source components are implementedJavax.sql.DataSourceInterface.Within Mybatis, third-party data source components are integrated, and data source implementations are provided.In general, data source initializat ...

Mysqldump is a logical backup method. Its biggest defect is that the speed of backup and recovery is slow. For a database less than 50G, this speed is acceptable. But if the database is very large, it is not suitable to use mysqldump backup again. At this time, you need a kind of easy-to-use and efficient tool. Xtrabackup is one of them, known ...

How to install MySQL on Ubuntu 20.04 MySQL is the most popular open source relational database management system. It's fast, easy to use, easy to expand, and part of the popular LAMP and LEMP. This guide explains how to install and protect MySQL on Ubuntu 20.04. prerequisite Make sure you are logged in as sudo user Install MySQL on Ubuntu At th ...

Because an interface is too slow... Try to optimize (/ baldness) Spring data used- mongo:2.1.3 mongo driver: 3.8.2 You can see me First query sentence. Optimization ideas paging Original page query Due to the large amount of data, the query was slow, and it was later found that there was no need to use aggregation at all. With aggregate que ...

On Jetpack(1) - ViewModelOn Jetpack(2) - LifecyclesOn Jetpack(3) - LiveDataDemo project Although Android carries SQLite, its operation is troublesome, and if it is a large-scale project, it will become confusing and difficult to maintain, unless you design a very good architecture and package. Of cour ...

Find the order status of the customer, which is displayed as: customer ID, company name, order ID, employee ID select customers.CustomerID,customers.CompanyName,orders.OrderID,orders.EmployeeID from customers,orders where orders.CustomerID=customers.CustomerID and orders.ShipCity=customers.City ord ...

Preface Ten suggestions for Java exception handling, I hope to help you ~ This article has been uploaded to github: https://github.com/whx123/Jav... Public number: A little boy collecting snails First, try not to use e.printStackTrace(), but to use log printing. Counterexamples: try{ // do what you want }catch(Exception e){ e.printStackTr ...

J2WEB course design example I found a good article about database query display error: Analysis of mysql coding errors. And then I have a crack free version navicat . extraction code: dv6k catalog Project Name: xixijiaxiang online e-book City Project background: (if I think about it myself, I won ...

catalog Delay loading Implement delayed loading Delay loading using allocation Using Collection to delay loading Delay loading It is to load data when it is needed, and not to load data when it is not needed. Lazy loading is also called lazy loading Advantages: query from single table first, ...

Article catalog preface Introducing pagehelper dependency application.yml Medium configuration Add interface Test paging query interface Problem summary application.yml Configuration of pagehelper in preface If you use mybatis to write paging query, it's troublesome. You need to write the select ...