The latest articles on DEV Community by Sam Fisher (@fisher_51). https://dev.to/fisher_51 https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F4211023%2Fff9964c6-7b0e-480c-9295-4c81b2f2beef.jpg https://dev.to/fisher_51 en Sam Fisher Tue, 27 Oct 2026 15:26:14 +0000 https://dev.to/fisher_51/dbt-tests-that-actually-catch-bad-data-a80 https://dev.to/fisher_51/dbt-tests-that-actually-catch-bad-data-a80 <p>Most dbt test suites I've inherited check <code>not_null</code> and <code>unique</code> and not much else. Those catch schema problems, not business problems.</p> <p>The tests that have saved us:</p> <ul> <li> <code>accepted_values</code> for status columns (catch typo'd statuses)</li> <li>A <code>relationships</code> test on every foreign key</li> <li>A custom test for "row count per day should be within 30% of last week"</li> <li>Freshness checks on source tables</li> </ul> <p>The custom tests took an afternoon and have caught two silent pipeline failures.</p> <p>I'm learning GraphQL next, mostly because our analytics API is moving that direction. Data people: how are you testing your marts?</p> dataengineering dbt testing