MODULE 3 · Working across tables

Reviewing a query

Reviewing a query

A query can run successfully and still answer the wrong question. Review its columns, filters, joins, grouping, and ordering before sharing the output.

Learning objectives

• Review a query for correctness
• Test a query with a limited result

Use a repeatable checklist before relying on a query result. Focus on explaining each decision in your own words before relying on a pattern or shortcut.

Example

SELECT id, total
FROM orders
WHERE status = 'paid'
ORDER BY created_at DESC
LIMIT 20;

Summary

Your progress is saved on this device. Sign in to keep it across devices.