SELECT

s.user_id,

ROUND(

COALESCE(

SUM(

CASE WHEN ACTION = 'confirmed' THEN 1 END

) / COUNT(*), 0),2)

AS confirmation_rate

FROM Signups s

LEFT JOIN Confirmations c

ON s.user_id = c.user_id

GROUP BY s.user_id;

[620. Not Boring Movies](https://leetcode.com/problems/not-boring-movies)

SELECT *

FROM Cinema

WHERE id % 2 <> 0

AND description <> "boring"

ORDER BY rating DESC

[1251. Average Selling Price](https://leetcode.com/problems/average-selling-price/)

SELECT p.product_id,

ROUND(SUM(price * units) / SUM(units), 2) AS average_price

FROM Prices p

LEFT JOIN UnitsSold s

ON p.product_id = s.product_id

AND purchase_date BETWEEN start_date AND end_date

GROUP BY p.product_id

[1075. Project Employees I](https://leetcode.com/problems/project-employees-i)

SELECT project_id, ROUND(AVG(experience_years), 2) average_years

FROM Project p

LEFT JOIN Employee e

ON p.employee_id = e.employee_id

GROUP BY project_id