How to Test Database Operations in Vibecoded Apps

Test every Create, Read, Update, and Delete operation in your app through the UI and directly against the API. Verify that creating a record inserts the correct data with all required fields. AI-generated code sometimes maps form fields to database columns incorrectly or drops fields silently during save.

Test updates by changing each field individually and in combination, then re-reading the record to confirm changes persisted. Pay attention to timestamps — updated_at fields should change on update. For deletes, verify that soft deletes actually mark records as deleted without removing them, and that hard deletes cascade correctly to related records.

Test unique constraints by attempting to create duplicate records. AI-generated schema migrations often define unique fields in the ORM model but forget to add the actual database constraint, meaning duplicates can exist if someone bypasses the application layer. Verify that foreign key constraints prevent orphaned records — deleting a parent should either cascade to children or be blocked.

Test concurrent operations to check for race conditions. Open two browser tabs, load the same record, edit it in both, and save both. Without proper optimistic locking or conflict resolution, the second save will silently overwrite the first. AI-generated code almost never handles concurrent writes correctly.

Add a realistic amount of test data — at least 10,000 records for main tables — and test that list pages, search, and filters remain responsive. AI-generated queries often work fine with 10 records but become unacceptably slow at scale. Use your database's query analyzer (EXPLAIN in PostgreSQL or MySQL) to check for full table scans and missing indexes.

Test pagination by navigating to late pages (page 100+). Many vibecoded apps use offset-based pagination that gets slower on later pages. Also check that N+1 query problems are not present — loading a list of 20 items should not trigger 21 separate database queries. Monitor your database logs during testing to count actual queries executed.