Course Introduction：不同数据库系统添加列的语法为：MySQL：ALTER TABLE table_name ADD column_name data_type;PostgreSQL：ALTER TABLE table_name ADD COLUMN column_name data_type;Oracle：ALTER TABLE table_name ADD (column_name data_type);SQL Server：ALTER TABLE table_name ADD column_name data_

2025-04-09 comment 0  1285

Course Introduction：为 Git 添加环境变量的方法：修改 .gitconfig 文件。 Add env = KEY=VALUE in the [core] block. Save and exit the file.重新加载 Git 配置（git config --reload）。验证环境变量（git config --get core.env.MY_ENV_VAR）。

2025-04-17 comment 0  1091

Course Introduction：2025年十大交易所排名依次为：币安、欧易、火币、Coinbase、Kraken、Bitfinex、Bittrex、Poloniex、Bitstamp和Gemini。 These exchanges have attracted much attention due to their advantages such as transaction volume, user base, transaction pair diversity, security measures and compliance, and are suitable for users with different needs.

2025-05-22 comment 0  276

Course Introduction：现代家庭通常有多个设备同时连接Wi-Fi访问网络，这常常导致带宽紧张，尤其是在进行在线游戏或视频流媒体等高带宽需求活动时。 为了帮助您管理网络负载，一些路由器（例如Google、Netgear、Eero等厂商生产的路由器）提供了一种名为“服务质量”（QoS）的功能。 Simply put, it allows you to prioritize specific devices and traffic types on your Wi-Fi network so that those devices and traffic can prioritize high-speed connections when bandwidth is limited. Your router vendor may use a different name to call this feature, but a quick lookup of the instructions or searching online should determine if your router provides QoS capabilities

2025-02-25 comment 0  808

Course Introduction：In front-end development, when using jQuery's load() method to load HTML content asynchronously, if you try to manipulate these newly loaded DOM elements through JavaScript immediately, you may encounter the error of document.getElementById(...) is null.这是因为JavaScript在内容完全加载并添加到DOM之前就已经执行了。本文将详细讲解此问题的原因，并提供使用load()方法的回调函数来确保内容加载完成后再进行DOM操作的解决方案。

2025-08-15 comment 0  442

Course Elementary  13859

Course Introduction：Scala Tutorial Scala is a multi-paradigm programming language, designed to integrate various features of object-oriented programming and functional programming.

Course Elementary  82403

Course Introduction："CSS Online Manual" is the official CSS online reference manual. This CSS online development manual contains various CSS properties, definitions, usage methods, example operations, etc. It is an indispensable online query manual for WEB programming learners and developers! CSS: Cascading Style Sheets (English full name: Cascading Style Sheets) is an application used to express HTML (Standard Universal Markup Language).

Course Elementary  13209

Course Introduction：SVG is a markup language for vector graphics in HTML5. It maintains powerful drawing capabilities and at the same time has a very high-end interface to operate graphics by directly operating Dom nodes. This "SVG Tutorial" is intended to allow students to master the SVG language and some of its corresponding APIs, combined with the knowledge of 2D drawing, so that students can render and control complex graphics on the page.

Course Elementary  24663

Course Introduction：In the "AngularJS Chinese Reference Manual", AngularJS extends HTML with new attributes and expressions. AngularJS can build a single page application (SPAs: Single Page Applications). AngularJS is very easy to learn.

Course Elementary  27514

Course Introduction：Go is a new language, a concurrent, garbage-collected, fast-compiled language. It can compile a large Go program in a few seconds on a single computer. Go provides a model for software construction that makes dependency analysis easier and avoids most C-style include files and library headers. Go is a statically typed language, and its type system has no hierarchy. Therefore users do not need to spend time defining relationships between types, which feels more lightweight than typical object-oriented languages. Go is a completely garbage-collected language and provides basic support for concurrent execution and communication. By its design, Go is intended to provide a method for constructing system software on multi-core machines.