Joins SQL interview questions
Interviewers use joins to check whether you understand table grain. Watch for LEFT JOIN conditions that belong in ON, anti-joins with NOT EXISTS, and joins that silently duplicate rows.
- Revenue by Product CategoryfreeAggregation & GROUP BY · Joinseasy
- Customers Who Never OrderedfreeJoinseasy
- Fare per Kilometer by Vehicle TypeJoins · Aggregation & GROUP BYeasy
- Drivers with Low RatingsAggregation & GROUP BY · Joinseasy
- Drivers with No Completed Trips in MarchfreeJoins · Subqueries & CTEseasy
- Accounts with More Than 5 UsersAggregation & GROUP BY · Joinseasy
- Account Activity SummaryJoins · Aggregation & GROUP BYeasy
- Click-Through Rate by ChannelfreeAggregation & GROUP BY · Joinseasy
- Cost per Click by CampaignAggregation & GROUP BY · Joinseasy
- Days with Impressions but No ClicksAggregation & GROUP BY · Joinseasy
- Reconcile Daily Clicks with Click LogsJoins · Aggregation & GROUP BYeasy
- Returned Value Share by CategoryConditional Aggregation · Joinsmedium
- Top 2 Earning Drivers in Each CityWindow Functions · Ranking & Top-N per Groupmedium
- Five-Star Share by Vehicle TypeConditional Aggregation · Joinsmedium
- 7-Day Activation Rate by ChannelFunnels & Activation · Joinsmedium
- Event Mix by Acquisition ChannelConditional Aggregation · Joinsmedium
- Campaigns That Overspent Their BudgetConditional Aggregation · Joinsmedium
- Users Who Clicked Ads on Every ChannelJoins · Aggregation & GROUP BYmedium
- Click-to-Purchase Rate by CampaignJoins · Subqueries & CTEsmedium
- Last-Touch Attribution by ChannelfreeMarketing Attribution · Window Functionshard
- Linear Attribution and ROAS by ChannelMarketing Attribution · Subqueries & CTEshard