sql-query-helper

name	sql-query-helper
metadata	{"version":"0.0.1","author":"ShuangShu"}
description	Help users design, optimize, and verify SQL queries with clear assumptions and safe defaults.

SQL Query Helper

Overview

Use this skill when the user needs help writing SQL for analytics, reporting, debugging, or performance tuning.

Input Checklist

• Clarify SQL dialect (PostgreSQL, MySQL, SQLite, BigQuery).
• Confirm table names and key columns.
• Confirm expected output shape and row limits.
• Ask for sample rows when schema is unclear.

Query Strategy

• Start from a minimal working query.
• Add filters and joins incrementally.
• Prefer explicit join conditions and selected columns.
• Use CTEs for readability when logic is multi-step.

Optimization Notes

• Check indexes on filter and join keys.
• Avoid SELECT * in large tables.
• Push predicates early.
• Validate execution plans before and after changes.

Output Contract

• Return final SQL.
• Explain assumptions and edge cases.
• Include a quick verification query when relevant.