Dataford
Interview QuestionsInterview GuidesExperiencesMock InterviewsPricing
Get started
7-Day Rolling Average Orders
00:00
5 left

7-Day Rolling Average Orders

MediumSQL · PostgreSQL

Problem

Write a SQL query to calculate a 7-day rolling average of daily orders by store using window functions at Target.

Use the provided stores and orders tables. Include calendar dates with no orders so they contribute zero to the daily count. Treat the rolling average as the average of the current date and up to the six preceding calendar dates.

Output

  1. One row per store and calendar date.
  2. Columns: store_id, store_name, order_date, daily_orders, and rolling_7_day_avg.
  3. Include all stores and dates in the order data's overall date range.
  4. Sort by store_id, then order_date.

Schema

stores
ColumnTypeDescription
store_idPKINTUnique Target store identifier
store_nameVARCHAR(100)Target store display name
orders
ColumnTypeDescription
order_idPKINTUnique order identifier
store_idINTStore where the order was placed
customer_idVARCHAR(30)Customer identifier associated with the order
order_dateDATECalendar date when the order was placed
Tablesstoresorders
Interviewer

Your question is 7-Day Rolling Average Orders. 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.

You need to log in / sign up to run or submit.
CodePostgreSQL
You need to log in / sign up to run or submit.Ln 1
Run your query to see results here.