Course Introduction：Difference Between DDL, DML, DCL, and TCL SQL commands are divided into categories based on their functionality. Here’s an explanation of the differences between DDL, DML, DCL, and TCL, along with examples: 1. DDL (Data Definition

2024-12-20 comment 0  634

Course Introduction：Introduction Transaction Control Language (TCL) commands are essential in SQL for managing changes made by Data Manipulation Language (DML) statements. These commands allow database administrators and users to control transaction processes, thereby

2025-04-22 comment 0  498

Course Introduction：SQL commands are mainly divided into four categories: DDL, DML, DCL and TCL. 1. DDL (data definition language) is used to define the database structure, including CREATE, ALTER, DROP, TRUNCATE and other commands; 2. DML (data operation language) is used to operate data, including SELECT, INSERT, UPDATE, DELETE; 3. DCL (data control language) is used to define permission management, including GRANT and REVOKE; 4. TCL (transaction control language) is used for transaction processing, including COMMIT, ROLLBACK and SAVEPOINT. These categories correspond to different management and operational functions of the database.

2025-07-01 comment 0  234

Course Introduction：Why Are Multiple Instances of Tk Discouraged?Tkinter, a Python wrapper around Tcl's Tk library, creates an instance of a Tcl interpreter when a...

2025-01-04 comment 0  1124

Course Introduction：This article explores the programming languages used in MySQL's core, focusing on C, C , and additional languages like Assembly, Perl, Shell scripts, Python, Java, Tcl, and Lua.

2024-12-30 comment 0  689

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.