Top 3 Transactions per Client | Dataford Interview Questions

Write a SQL query to identify the top 3 transactions per client per month using window functions.

Use the available client and transaction data. Rank higher transaction amounts first, breaking ties by earlier transaction timestamp and then lower transaction ID.

Output

Return one row per selected transaction with client_id, client_name, transaction_month, transaction_id, amount, and transaction_rank.
Include no more than three rows per client and calendar month. Clients with fewer than three transactions may have fewer rows.
Order by client_id, transaction_month, and transaction_rank ascending.

Schema

clients

Column	Type	Description
client_idPK	INT	Unique client identifier
client_name	VARCHAR(150)	Client display name
segment	VARCHAR(50)	Client business segment

transactions

Column	Type	Description
transaction_idPK	INT	Unique transaction identifier
client_id	INT	Client associated with the transaction
transaction_timestamp	TIMESTAMP	Timestamp when the transaction occurred
amount	NUMERIC(14,2)	Transaction amount

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