Calculate Daily Harmful Content View Percentage

Q: How do I practice SQL interview questions?

PracHub provides an interactive SQL console where you can write and test queries against real database schemas. Get instant feedback and compare your solution with the expected output.

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.

Quick Overview

Calculate Daily Harmful Content View Percentage