gaku52/06-data-and-security/sql-and-query-mastery
06-data-and-security/sql-and-query-mastery/SKILL.md
[日本語版](../../ja/06-data-and-security/sql-and-query-mastery/SKILL.md) # SQL and Query Mastery > SQL is the universal language of data manipulation. This skill systematically covers everything from basic syntax to advanced window functions, query optimization, execution plan analysis, and database-specific features. ## Target Audience - Engineers who want to learn SQL systematically - Developers looking to optimize query performance - Those involved in database design and operations ## Prereq
$ install --global
skillsauthnpx skillsauth add gaku52/claude-code-skills 06-data-and-security/sql-and-query-masteryInstall this skill globally with one command. Works with Claude Code, Cursor, and Windsurf.
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95%
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50%
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50%
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Last scanned: May 11, 2026, 2:26 AM37.1s20 files scanned
SKILL.md
日本語版
SQL and Query Mastery
SQL is the universal language of data manipulation. This skill systematically covers everything from basic syntax to advanced window functions, query optimization, execution plan analysis, and database-specific features.
Target Audience
- Engineers who want to learn SQL systematically
- Developers looking to optimize query performance
- Those involved in database design and operations
Prerequisites
- Foundational understanding of relational databases
- Basic SQL knowledge (SELECT/INSERT/UPDATE/DELETE)
Study Guide
00-basics — SQL Fundamentals
| # | File | Description | |---|------|-------------|
01-advanced — Advanced SQL
| # | File | Description | |---|------|-------------|
02-optimization — Query Optimization
| # | File | Description | |---|------|-------------|
03-specific — Database-Specific Features
| # | File | Description | |---|------|-------------|
Quick Reference
SQL Performance Checklist:
✓ Verify execution plans with EXPLAIN ANALYZE
✓ Create appropriate indexes
✓ Avoid SELECT *; query only the columns you need
✓ Resolve N+1 queries with JOINs
✓ For large datasets, use cursor-based pagination instead of LIMIT/OFFSET
✓ Perform aggregations on the database side
References
- PostgreSQL. "Documentation." postgresql.org/docs, 2024.
- Winand, M. "SQL Performance Explained." use-the-index-luke.com, 2012.
- Molinaro, A. "SQL Cookbook." O'Reilly, 2020.
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