7-Day Rolling Average Balance Query | Dataford Interview Questions

Given a table of daily user balances, write a query to calculate the 7-day rolling average balance for every user at Current (NY).

Assume each row represents a user's balance on a calendar date. The seven-day period includes the current date and six preceding calendar days; missing dates are excluded, and NULL balances are ignored.

Output

One row per user and balance date.
Columns: user_id, balance_date, and rolling_avg_balance.
Sort by user_id, then balance_date ascending.

Schema

daily_user_balances

Column	Type	Description
balance_idPK	INT	Unique balance record identifier
user_id	INT	Current user identifier
balance_date	DATE	Date represented by the balance
balance	DECIMAL(12,2)	User balance on the recorded date

Your question is 7-Day Rolling Average Balance Query. Start with the requirements and the one table 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.

Problem

Given a table of daily user balances, write a query to calculate the 7-day rolling average balance for every user at Current (NY).

Output

One row per user and balance date.
Columns: user_id, balance_date, and rolling_avg_balance.
Sort by user_id, then balance_date ascending.

Schema

daily_user_balances

Column	Type	Description
balance_idPK	INT	Unique balance record identifier
user_id	INT	Current user identifier
balance_date	DATE	Date represented by the balance
balance	DECIMAL(12,2)	User balance on the recorded date

Your question is 7-Day Rolling Average Balance Query. Start with the requirements and the one table 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.