Databases · Middle · Question 32 of 75

What is `COUNT(*) FILTER (WHERE status = 'paid')` used for?

1Counting rows that have no status
✓Correct answer: Counting only matching rows inside an aggregate, so one query can return several counts
3Filtering the whole result before counting

Explanation

For example COUNT(*) FILTER (WHERE status = 'paid') AS paid, COUNT(*) FILTER (WHERE status = 'new') AS new in a single pass.

Further reading

PostgreSQL: Aggregate functions reference ↗

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