Code RoomJoin multiplies refund rows

HardPrep Room Coding #2329

Join multiplies refund rows

Code reviewCode quality & reviewSenior~18 min

Review this query that sums order totals per customer.

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0:00 of about 18 min

Mark a line and say what kind of problem it is.0 findings

1SELECT c.id, SUM(o.total)

2FROM customers c

3JOIN orders o ON o.customer_id = c.id

4JOIN refunds r ON r.customer_id = c.id

5GROUP BY c.id;

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