UPDATE and DELETE in MySQL
UPDATE
UPDATE users SET status = 'inactive' WHERE id = 5;
UPDATE products
SET price = price * 0.9, updated_at = NOW()
WHERE category_id = 3;
-- Update with JOIN
UPDATE orders o
JOIN users u ON o.user_id = u.id
SET o.status = 'vip'
WHERE u.tier = 'gold';
DELETE
DELETE FROM sessions WHERE expires_at < NOW();
DELETE FROM orders WHERE user_id = 10 LIMIT 100;
SOFT DELETE Pattern
ALTER TABLE users ADD COLUMN deleted_at TIMESTAMP NULL;
-- Soft delete
UPDATE users SET deleted_at = NOW() WHERE id = 5;
-- Query active
SELECT * FROM users WHERE deleted_at IS NULL;