SQL 문제집 Level 10.9

다음 테이블들이 주어집니다:

users
id name registration_date
1 John 2022-05-10
2 Max 2022-01-10
3 Andrew 2022-10-31
4 Joe 2022-11-30
5 Karl 2022-07-31
ad_clicks
id user_id click_date
1 3 2023-12-06
2 1 2023-12-05
3 2 2023-12-01
4 5 2023-11-12
5 4 2023-11-11
6 1 2023-10-14
7 2 2023-10-10
8 3 2023-11-30
9 4 2023-12-05
10 4 2023-12-01
11 5 2023-12-08
12 3 2023-11-27
13 2 2023-11-28
14 1 2023-12-09
15 5 2023-12-10
16 5 2023-11-30
17 2 2023-11-12
purchases
id user_id date
1 3 2023-12-12
2 1 2023-12-05
3 2 2023-12-01
4 5 2023-11-12
5 4 2023-11-11
6 1 2023-10-14
7 2 2023-10-10
8 3 2023-11-30
9 4 2023-12-05
10 4 2023-12-01
11 5 2023-12-08
12 3 2023-11-27
13 2 2023-11-28
14 1 2023-12-09
15 5 2023-12-10
16 5 2023-11-30
17 2 2023-11-12

다음 문제들을 해결하세요:

Задание 1

전환율과 클릭 비용을 기준으로 광고 캠페인의 효과를 평가하세요.