sql-best-practices

# 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.