Tricky~20min

The Vaccine Given Twice in One Day

5 pets got the SAME vaccine twice on the same day at two different clinic locations in the chain — a duplicate administration nobody caught because the two locations don't share real-time records. 8 other pets also have two vaccine records the same day, but they're two different vaccine types — a normal combo visit.

Tables you'll query

petsvaccine_records

What you'll learn

Aggregations & GROUP BY
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