Subqueries & CTEs SQL interview questions
Complex questions are easier as a chain of CTEs: one step per idea. Interviewers reward readable decomposition as much as the final answer.
- Average Order Value by CountryfreeAggregation & GROUP BY · Subqueries & CTEseasy
- Products Priced Above Their Category AverageWindow Functions · Subqueries & CTEseasy
- Drivers with No Completed Trips in MarchfreeJoins · Subqueries & CTEseasy
- Repeat Purchase RateSubqueries & CTEs · Aggregation & GROUP BYmedium
- Days from Signup to First OrderDates & Time · Subqueries & CTEsmedium
- Referral LeaderboardSelf-Joins · Aggregation & GROUP BYmedium
- Riders Active in January but Not MarchSubqueries & CTEs · Dates & Timemedium
- DAU/MAU Stickiness for MarchDates & Time · Subqueries & CTEsmedium
- Hours from Signup to First ProjectDates & Time · Subqueries & CTEsmedium
- Paying Accounts with No Recent ActivitySubqueries & CTEs · Dates & Timemedium
- Users Who Clicked Ads on Every ChannelJoins · Aggregation & GROUP BYmedium
- Click-to-Purchase Rate by CampaignJoins · Subqueries & CTEsmedium
- Hours from First Click to PurchaseDates & Time · Subqueries & CTEsmedium
- 90-Day Repeat Rate by First-Order CohortRetention & Cohorts · Subqueries & CTEshard
- Customers Who Bought in Every Quarter of 2025Subqueries & CTEs · Dates & Timehard
- Customers Who Make Up Half of RevenueRunning Totals & Rolling Windows · Window Functionshard
- Hours with Above-Average PricingSubqueries & CTEs · Dates & Timehard
- New vs Returning Riders by MonthRetention & Cohorts · Subqueries & CTEshard
- Ordered Activation FunnelfreeFunnels & Activation · Subqueries & CTEshard
- Weekly Signup Cohort RetentionRetention & Cohorts · Dates & Timehard
- Linear Attribution and ROAS by ChannelMarketing Attribution · Subqueries & CTEshard