Performing Conditional Updates with CASE WHEN

UPDATE products
SET
    price = CASE
        WHEN category_id = 1 THEN price * 1.10 -- Increase price by 10% for category 1
        WHEN category_id = 2 THEN price * 1.05 -- Increase price by 5% for category 2
        ELSE price -- Keep original price for other categories
    END,
    last_updated_at = NOW()
WHERE
    category_id IN (1, 2, 3); -- Apply to relevant categories

How it works: This SQL snippet demonstrates how to perform conditional updates on a table. The `CASE WHEN` statement allows you to specify different update actions for a column (`price` in this example) based on various conditions (`category_id`). If `category_id` is 1, the price increases by 10%; if 2, it increases by 5%. For other categories, the price remains unchanged. The `WHERE` clause can further narrow down the rows affected by the update.