SQL practice: The Order Things Actually Happen
Chapter 32 · 6 questions · included in full access
Question 1 · easy
Solve it in your browserWhy does WHERE COUNT(*) > 5 always error?
Question 2 · easy
Solve it in your browserWhy does an AS alias work in ORDER BY but not in WHERE?
Question 3 · medium
Solve it in your browserWhy can't you filter on ROW_NUMBER() in the same query that creates it?
Question 4 · medium
Solve it in your browserBetween WHERE branch_id = 1 and HAVING branch_id = 1 on a grouped query, which is faster and why?
Question 5 · hard
Solve it in your browserA query has a JOIN and a WHERE. Which happens first, and why does that matter for a LEFT JOIN?
Question 6 · hard
Solve it in your browserWhy can HAVING use COUNT(*) when WHERE cannot?
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