http://www.heyuan110.com/tags/index/Recent content in Index on Bruce on AI EngineeringHugoenFri, 23 Jan 2026 20:06:36 +0800http://www.heyuan110.com/posts/mysql/2026-01-23-mysql-sql-complete-guide/Fri, 23 Jan 2026 20:06:36 +0800http://www.heyuan110.com/posts/mysql/2026-01-23-mysql-sql-complete-guide/<p><img src="http://www.heyuan110.com/posts/mysql/2026-01-23-mysql-sql-complete-guide/cover.webp" alt="MySQL SQL Complete Guide: From Beginner to Advanced" loading="lazy" decoding="async" fetchpriority="low" width="1200" height="675" /> </p> <p><strong>SQL (Structured Query Language)</strong> is the universal language for communicating with databases. Whether you are a backend developer, data analyst, or DevOps engineer, SQL proficiency is a must-have skill. This guide uses MySQL as the reference implementation and walks you through everything from basic syntax to the internals that interviewers love to ask about.</p> <blockquote> <p>This is a long-form article (~15,000 words). Bookmark it and work through one section at a time. Use the table of contents to jump to the topics you need.</p>http://www.heyuan110.com/posts/mysql/2019-09-06-mysql-explain/Fri, 06 Sep 2019 20:10:21 +0800http://www.heyuan110.com/posts/mysql/2019-09-06-mysql-explain/<p><img src="http://www.heyuan110.com/posts/mysql/2019-09-06-mysql-explain/cover.webp" alt="MySQL EXPLAIN execution plan analysis" loading="lazy" decoding="async" fetchpriority="low" width="1200" height="675" /> </p> <p><strong>EXPLAIN</strong> is the single most useful tool for understanding MySQL query performance. When a query runs slower than expected, the first thing you should do is prefix it with EXPLAIN to inspect the execution plan. It reveals how MySQL processes your query &ndash; which indexes it picks, how many rows it expects to scan, and what join strategy it uses.</p> <p>This guide walks through every field in the EXPLAIN output so you can quickly pinpoint performance bottlenecks.</p>