SQL Churn via Purchase Gaps | Dataford Interview Questions

Write a query to identify customer churn patterns by calculating the time gap between consecutive purchases for each user.

Use the users and purchases tables. Classify a gap of at least 90 days as churn_risk; shorter gaps are active.

Output

One row per purchase that has a previous purchase by the same user.
Return user_id, user_name, purchase_id, purchase_date, previous_purchase_date, gap_days, and churn_status.
Order by user_id, purchase_date, and purchase_id ascending.

users

purchases

Your question is SQL Churn via Purchase Gaps. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Write a query to identify customer churn patterns by calculating the time gap between consecutive purchases for each user.

Use the users and purchases tables. Classify a gap of at least 90 days as churn_risk; shorter gaps are active.

One row per purchase that has a previous purchase by the same user.
Return user_id, user_name, purchase_id, purchase_date, previous_purchase_date, gap_days, and churn_status.
Order by user_id, purchase_date, and purchase_id ascending.

users

purchases

Your question is SQL Churn via Purchase Gaps. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.