1.8Find Data Anomalies

These queries hunt for data integrity issues that indicate bugs in your application.

-- Find orphaned records (line items without orders)
SELECT li.id, li.order_id
FROM line_items li
LEFT JOIN orders o ON o.id = li.order_id
WHERE o.id IS NULL;

-- Find duplicate emails (data integrity issue)
SELECT email, COUNT(*)
FROM users
GROUP BY email
HAVING COUNT(*) > 1;

-- Find NULL values in required fields
SELECT id, name, email
FROM users
WHERE name IS NULL OR email IS NULL;