Tricky~21min

The Validated Ticket That Still Got Billed

10 parking sessions were charged an exit fee even though the merchant validation was still valid at exit time — the gate isn't checking validation status before charging. 20 more sessions were also charged despite having a validation on file, but that validation had already expired before the customer left, so charging those is correct.

Tables you'll query

parking_sessionsvalidations

What you'll learn

JOINsDate & Time Functions
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