User Contest Attendance
Meta
Problem Statement
Engagement teams at Meta want to track which contests are most popular among the user base. You need to determine the registration percentage for every contest.
Write an SQL query to find the percentage of the users registered in each contest rounded to two decimals.
Rules:
- The percentage is calculated as (Users Registered in Contest / Total Users in Users Table) * 100.
- Round the result to exactly 2 decimal places.
- Return the contest_id and the percentage.
- Results must be sorted by percentage in descending order. In case of a tie, sort by contest_id in ascending order.
Tests your understanding of
Basic SQL, Aggregation, Subquery, Rounding and Math Functions
Input Tables
users
| user_id(INTEGER) | user_name(VARCHAR) |
|---|---|
| 6 | Alice |
| 2 | Bob |
| 7 | Alex |
register
| contest_id(INTEGER) | user_id(INTEGER) |
|---|---|
| 215 | 6 |
| 209 | 2 |
| 208 | 2 |
| 210 | 6 |
| 208 | 6 |
| 209 | 7 |
| 209 | 6 |
| 215 | 7 |
| 208 | 7 |
| 210 | 2 |
| 207 | 2 |
| 210 | 7 |
Expected Output
| contest_id(INTEGER) | percentage(FLOAT) |
|---|---|
| 208 | 100 |
| 209 | 100 |
| 210 | 100 |
| 215 | 66.67 |
| 207 | 33.33 |
Tags
EasyBasic SQLAggregationSubqueryRoundingMath Functions
10-15 min
65%