Calculate Daily Harmful Content View Percentage

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Q: What difficulty level is this coding question?

This is a Medium difficulty Data Manipulation (SQL/Python) question, commonly asked during Technical Screen rounds at Meta.

Q: What role is this question designed for?

This question is commonly asked for Data Scientist candidates at Meta during technical interviews.

Question

VIDEOS

+----+-------------+------------+
| id | uploader_id | is_harmful |
+----+-------------+------------+
| 1  | 101         | true       |
| 2  | 102         | false      |
| 3  | 101         | true       |
+----+-------------+------------+

​

VIEWS

+----------+---------+---------------------+
| video_id | user_id | view_time           |
+----------+---------+---------------------+
| 1        | 1001    | 2023-07-01 10:00:00 |
| 2        | 1002    | 2023-07-01 10:01:00 |
| 1        | 1003    | 2023-07-01 10:02:00 |
+----------+---------+---------------------+

##### Scenario

A video-sharing platform wants to quantify how often users watch harmful content.

##### Question

Using the provided tables, write a SQL query that returns daily view_prevalence – the percentage of all views in a day that were on videos flagged as harmful.

##### Hints

Join videos to views; use SUM(CASE…) / COUNT(*) grouped by DATE(view_time).

PracHub · Accepted Answer

This question evaluates proficiency in data manipulation and aggregation for computing event-based metrics, testing competency in SQL/Python data processing within the Data Manipulation (SQL/Python) domain.

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