SQL for Inactive Accounts | Dataford Interview Questions

How would you write a SQL query to identify active customer accounts that have not made a transaction in the last ninety days at Point Digital Finance?

Assume the evaluation date is 2025-04-01. Include accounts with no transaction history, and treat the 90-day window as inclusive of its start date.

Output

One row per qualifying account with account_id, customer_name, account_status, and opened_date
Include only active accounts without a transaction in the window
Sort by account_id ascending

Schema

customer_accounts

Column	Type	Description
account_idPK	INT	Unique customer account identifier
customer_name	VARCHAR(100)	Customer's full name
account_status	VARCHAR(20)	Current account status
opened_date	DATE	Date the account was opened

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
account_id	INT	Account associated with the transaction
transaction_at	TIMESTAMP	Timestamp when the transaction occurred
transaction_type	VARCHAR(30)	Transaction classification

Your question is SQL for Inactive Accounts. Start with the requirements and the two tables in the Question tab.

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Problem