SQL Tells You What. Comments Tell You Why.

The best SQL doesn’t need comments. Write meaningful CTE names, descriptive aliases, clear column labels — and a skilled reader will follow your logic without a single annotation. That’s the right instinct. It’s also only half right. SQL is a declarative language. You’re not writing how the database retrieves your data; you’re writing what you want. That’s a useful distinction, because “what” and “why” are very different questions, and SQL can answer exactly one of them.