A public account focused on workplace, career growth, team management, and self-improvement. The author is the writer of books including 'SpringBoot Technology Insider' and 'Drools 8 Rule Engine: Core Technology and Practice'.
This article explains the N+1 query performance issue, demonstrates a naïve Python/SQLite implementation that triggers N+1 queries, compares its runtime, and then shows how using SQL JOINs, GROUP BY, and nested data structures can dramatically improve query efficiency and reduce latency.
This guide walks through MySQL's join operations—inner, left, right, and full outer—using a simple grocery‑items schema, showing how to create tables, write correct queries, avoid common pitfalls like unintended cross joins, apply aliases, and filter unassociated rows with WHERE and UNION.
This guide explains why MySQL cannot index JSON columns directly and demonstrates two practical work‑arounds—using generated columns in MySQL 5.7 and functional indexes in MySQL 8.0.13—to efficiently index a nested request.email field for fast queries.
Drawing on interviews with hundreds of technical candidates, this article outlines practical resume‑screening criteria, the three key interview dimensions—problem‑solving, fundamentals, and soft skills—and compares the strengths of Go developers from Java, PHP, and native Go backgrounds.
This article explains the performance differences among MySQL's COUNT(*), COUNT(1), and COUNT(column) forms, showing that COUNT(*) and COUNT(1) are equivalent and generally faster than counting specific columns, and provides practical recommendations for accurate row counting.
This article explains the fundamental differences between MySQL VARCHAR and CHAR types, covering their definitions, length limits, storage overhead, character‑set effects, practical examples, and guidelines for choosing the appropriate column type in database design.
This article examines common misconceptions about MySQL VARCHAR—why 255 was historically used, the real maximum length, performance differences between short and long definitions, character‑set impacts on storage, and why aligning sizes to powers of two offers no real benefit.
The article compares traditional rule‑engine architectures with AI‑driven models, explains their differing characteristics, outlines when deterministic rule matching is preferable over flexible AI inference, and recommends practical technologies such as Drools for rule‑based solutions and LLM‑based RAG/Agent frameworks for AI‑centric scenarios.
An in‑depth tutorial walks through the five core SQL language families—DDL, DML, DQL, DCL, and TCL—explaining their purposes, key commands, and practical examples, while highlighting differences and usage tips for database schema definition, data manipulation, querying, permission control, and transaction management.
This tutorial walks through preparing a CentOS 8 server, uninstalling any existing Docker packages, adding a Tencent Cloud mirror, installing and starting Docker, configuring a non‑root Docker user group, and finally pulling, configuring, and running an Nginx container with essential HTTPS settings.
