Practice SQL Question | Real Coding Interviews

Quick Summary

Compute monthly metrics by analyzing per-customer order frequency.
Distinguish between all active customers and those exceeding a fixed order threshold within each month.
Calculate a rounded percentage ratio while handling potential division-by-zero or sparse data scenarios.

What This Tests

Multi-level aggregation requiring intermediate grouping before final summarization.
Conditional counting and ratio calculations across grouped datasets.
Date extraction and time-period bucketing for chronological analysis.
Graceful handling of edge cases where thresholds are not met or data is sparse.

Common Patterns

Groupby

Aggregation

Date Arithmetic

Accepted

18/56

Acceptance Rate32.1%

Test Cases

Input

Output

Expected