SQL Practice
Real-life business problems on real tables. Read the scenario, write the query, and get it checked instantly.
Expert50 pts
Best-selling product in each category
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Running total of revenue by month
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The second order that beat the first
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The typical basket: median order value by country
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Three swipes in ten minutes
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The deepest balance drawdown
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Most active card holder in every country
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The 30-day readmission rate per department
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The second-highest salary in every country
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Gaps and islands: every driver's longest working streak
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Drivers whose rating slid three weeks in a row
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Sessionization: the ten longest listening sessions
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VIP outreach: the top 10 percent of listeners
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