Solve SQL and Python Data Manipulation Tasks

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 Onsite rounds at Adobe.

Q: What role is this question designed for?

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

Question

UserEvents

+----+---------+------------+------------+
| id | user_id | event_type | event_date |
+----+---------+------------+------------+
| 1  | 101     | install    | 2023-05-01 |
| 2  | 101     | open_app   | 2023-05-01 |
| 3  | 102     | install    | 2023-05-01 |
| 4  | 103     | install    | 2023-05-02 |
| 5  | 103     | share      | 2023-05-02 |
+----+---------+------------+------------+

##### Scenario

Technical screen requiring simple SQL queries and basic Python data-structure manipulations on app event data.

##### Question

SQL:
1) Count distinct daily active users.
2) Return the three most common event_type values yesterday.
3) List users whose first recorded event was 'install'. Python: a) Given a dict, produce an inverted dict (values→keys). b) Remove duplicates from a list in one line. c) Reverse a string in one line.

##### Hints

Use GROUP BY with DISTINCT, ORDER BY … DESC LIMIT, window/aggregation for first_event; in Python leverage dict comprehensions, set(), slicing[::-1].

PracHub · Accepted Answer

This question evaluates proficiency in SQL event-log aggregation and basic Python data-structure transformations, assessing competencies such as counting distinct users, identifying frequent event types, and performing dictionary/list/string manipulations.

Quick Overview

Solve SQL and Python Data Manipulation Tasks