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Missing Invoice Serial Numbers

SQLMediumMid level~15 min

Problem

**[Classic — asked at multiple companies]**

The accounting team noticed gaps in invoice serial numbers.
Find all **missing serial numbers** between the minimum and maximum invoice IDs.

Return `missing_invoice_id`, ordered ascending.

Tables

Example rows — the live problem includes the full dataset.

invoices
invoice_id

Expected output

Your answer should return 2 rows with the columns missing_invoice_id.

Starter code (SQL)

SELECT *
FROM invoices;

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