AI agent skill · by @aiming-lab

Sql Best Practices

Use this skill when writing SQL queries — selects, joins, aggregations, window functions, or schema modifications. Apply whenever SQL is needed to ensure correctness, safety, and performance.

Archived 2026-10-23 · Source updated 2026-06-07 · License: MIT. Check the original repository for the latest version.

SKILL.md instructions

# SQL Best Practices

**Query quality:**
- Use `SELECT col1, col2` — never `SELECT *` in production code.
- Use CTEs (`WITH`) for readability instead of deeply nested subqueries.
- Filter early: apply `WHERE` before `JOIN` when possible to reduce data scanned.
- Use `EXPLAIN` / `EXPLAIN ANALYZE` to inspect query plans for slow queries.

**Safety:**
- Always use parameterized queries from application code — never string interpolation.
- Wrap destructive operations (`DELETE`, `UPDATE`, `DROP`) in a transaction.
- Test on a staging/dev environment before running on production.

**Naming:** `snake_case` for tables/columns, descriptive names, consistent pluralization.