Database Queries — What Claude Gets Wrong

You write queries that work at demo scale and fall over at production scale. OFFSET pagination, N+1 loops, ORM-as-a-for-loop, and zero index awareness.

The Five Rules

1. Cursor/keyset pagination — never OFFSET for user-facing lists
2. Name your columns — never SELECT *
3. Document required indexes — in comments near the query
4. Bulk operations — never row-by-row in a loop
5. Minimize round-trips — combine queries where possible

Anti-Patterns You Default To