Top 10 Users by Last Quarter | Dataford Interview Questions

Write a query to identify the top 10 users based on transaction volume over the last quarter.

Use the users and transactions tables. Count every transaction row in the previous completed calendar quarter, excluding rows with a NULL transaction_timestamp or user_id.

Output

One row per user with columns user_id, user_name, and transaction_volume
Include at most 10 users, ordered by transaction volume descending and user_id ascending for ties
Rows with a NULL timestamp or user ID are ignored

Schema

users

Column	Type	Description
user_idPK	INT	Unique identifier for a Groww user
user_name	VARCHAR(100)	Display name of the user

transactions

Column	Type	Description
transaction_idPK	INT	Unique identifier for a transaction
user_id	INT	User associated with the transaction
transaction_timestamp	TIMESTAMP	Timestamp when the transaction was recorded
amount	NUMERIC(18,2)	Transaction amount in Indian rupees
status	VARCHAR(40)	Current transaction status

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