Junior — Middle

Have you used subqueries inside other SQL queries when working with databases?

sobes.tech AI

Answer from AI

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 a total amount greater than the average across all orders, you can use a subquery:

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.

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