New Customers Per Day
A medium SQL mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- SQL
- Difficulty
- medium
- Seniority
- L5
Interview Prompt
For each calendar date, how many customers placed their very first order on that day? A customer's first-order date is the earliest order they have in the table.
Summary
Count users whose first order falls on each date.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your sql solution with real code execution
- Get instant feedback and a hire/no-hire decision