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Compare WHERE vs HAVING with aggregates

PayPalData Scientist · Onsite
MediumData ScientistOnsiteData Manipulation (SQL/Python)

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Compare WHERE vs HAVING with aggregates evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

Filter groups based on an aggregate and explain WHERE vs HAVING. Provide a query that returns merchants with chargeback_rate > 0.5% in the last 30 days using HAVING. Clarify why WHERE cannot reference aggregates, how HAVING works after GROUP BY, dialect differences (e.g., MySQL allowing expressions in HAVING without GROUP BY), and performance considerations.