Amazon
Medium
Data ScientistRetrieve First Active and Last Inactive Dates per User
Data Manipulation (SQL/Python)
166
9
August 4, 2025
SQL Aggregation Interview Questions
Aggregation questions test whether you can summarize data at the right grain using GROUP BY and HAVING.
Common themes include COUNT vs COUNT(DISTINCT), conditional aggregation with CASE, and aggregating after joins.
Interviewers look for correct groupings, handling of NULLs, and clear explanation of your logic.
145Questions
37Companies
Easy 1 • Medium 144 • Hard 0Difficulty mix
Common SQL aggregation interview patterns
- Choosing the correct grouping level
- HAVING vs WHERE for post-aggregation filters
- Conditional aggregation with CASE
- COUNT(DISTINCT) vs COUNT
- Aggregation after joins
- Top N per group with aggregation
SQL aggregation interview questions
Filter and sort
Instacart
Medium
Data ScientistCalculate Weekly Revenue and Order Count for Standard Deliveries
Data Manipulation (SQL/Python)
87
0
July 12, 2025
Pinterest
Medium
Data ScientistAnalyze Global Engagement and Impressions with SQL Queries
Data Manipulation (SQL/Python)
74
0
July 12, 2025
Coinbase
Medium
Data ScientistCalculate Cumulative Sum for Each Integer in Table
Data Manipulation (SQL/Python)
23
0
July 12, 2025
Uber
Medium
Data ScientistAnalyze User Purchase Behavior in Online Marketplace Data
Data Manipulation (SQL/Python)
63
1
July 12, 2025
LinkedIn
Medium
Data ScientistIdentify Top Contributors by Recent Post Count
Data Manipulation (SQL/Python)
86
0
July 12, 2025
Meta
Medium
Data ScientistAnalyze New Shops' Activity Compared to Existing Ones
Data Manipulation (SQL/Python)
89
0
July 12, 2025
Meta
Medium
Data ScientistAnalyze Conversation Engagement and Reaction Usage Effectively
Data Manipulation (SQL/Python)
173
3
July 12, 2025
Meta
Medium
Data ScientistAnalyze Group Call Adoption Using SQL Queries
Data Manipulation (SQL/Python)
152
1
July 12, 2025
DoorDash
Medium
Data ScientistWrite SQL for percent and window changes
Data Manipulation (SQL/Python)
30
0
October 13, 2025
Amazon
Medium
Data ScientistAnalyze User Engagement with SQL Queries
Data Manipulation (SQL/Python)
135
0
August 4, 2025
Meta
Easy
Data ScientistCompute ads revenue by geography in SQL
Data Manipulation (SQL/Python)
5
5
January 17, 2026
Meta
Medium
Data ScientistCalculate Engagement Metrics for Info-Stream Content Analysis
Data Manipulation (SQL/Python)
105
1
July 12, 2025
Capital One
Medium
Data ScientistCompute Customer Spend and Engineer Features for 2023
Data Manipulation (SQL/Python)
107
0
August 4, 2025
Amazon
Medium
Data ScientistExplain MySQL to MS SQL Server query syntax differences.
Data Manipulation (SQL/Python)
104
0
August 4, 2025
Twitch
Medium
Data ScientistAnalyze Streaming Data with SQL for Monthly Trends
Data Manipulation (SQL/Python)
98
0
July 12, 2025
Uber
Medium
Data ScientistCalculate January-2024 SF Promotion Impact Using SQL Queries
Data Manipulation (SQL/Python)
8
0
July 12, 2025
Chime
Medium
Data ScientistAnalyze Acquisition Channels for User Value and Retention
Data Manipulation (SQL/Python)
92
0
August 4, 2025
TikTok
Medium
Data ScientistCompute 7-Day Rolling Average of Unique Post Viewers
Data Manipulation (SQL/Python)
90
0
July 12, 2025
Meta
Medium
Data ScientistRetrieve Top Five Ads by Conversions in 30 Days
Data Manipulation (SQL/Python)
87
0
August 4, 2025
Common mistakes with SQL aggregation
- Grouping by too many columns
- Using WHERE instead of HAVING for aggregates
- Double counting after joins
- COUNT(column) skipping NULLs unintentionally
- Misusing DISTINCT on aggregated fields
How aggregation questions are evaluated in interviews
Correct grouping and filtering matter more than micro-optimizations.
Explain your grain, especially when combining joins and aggregates.
Call out assumptions about NULLs and duplicates.