Kas olete kasutanud alamklausitusi teistes SQL-päringutes andmebaasidega töötades?

Yes, I have used subqueries in SQL to solve tasks where it is necessary to obtain data dependent on the results of another query. For example, to select users who have orders with an amount greater than the average of all orders, a subquery can be used:

SELECT user_id, user_name
FROM users
WHERE user_id IN (
    SELECT user_id
    FROM orders
    GROUP BY user_id
    HAVING SUM(amount) > (
        SELECT AVG(total_amount) FROM (
            SELECT SUM(amount) AS total_amount FROM orders GROUP BY user_id
        ) AS avg_subquery
    )
);

Subqueries help make queries more flexible and expressive.