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#0324
Conditional Counts by Status
MediumSQL24 min20 XP
Problem
Return paid_count and cancelled_count from orders.
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
orders(order_id INTEGER, status TEXT)
Examples
Example 1
Inputtwo paid, one cancelled, one pending
Output2, 1
CASE creates 1/0 indicators that SUM can count.
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
Inputtwo paid, one cancelled, one pending
Expected[[2,1]]
CASE creates 1/0 indicators that SUM can count.
Hidden Test Categories
Empty or missing matchesDuplicate rows or tiesNULL values where the pattern commonly breaks