Back to Practice
#0361

Lowest Revenue Product Per Category

MediumSQL24 min20 XP

Problem

Return category, product, and revenue for the lowest revenue product in each category.

Why This Matters

SQL interviews usually test whether you can turn a business question into the right rows, grouping level, join type, and edge-case behavior.

Schema

sales(category TEXT, product TEXT, revenue INTEGER)

Examples

Example 1
Inputp2 and q2 are lowest in their categories
Outputp2 and q2

Sorting revenue ascending makes the lowest row rank 1.

Constraints

  • Return only the requested columns.
  • Use deterministic ORDER BY when multiple rows are returned.
  • Assume SQLite-compatible SQL unless the prompt states otherwise.
CodeSQL
Visible browser tests run here when available.
Testcases1 visible / 3 hidden categories
Core SQL case
Inputp2 and q2 are lowest in their categories
Expected[["A","p2",80],["B","q2",40]]

Sorting revenue ascending makes the lowest row rank 1.

Hidden Test Categories
Empty or missing matchesDuplicate rows or tiesNULL values where the pattern commonly breaks