Top-Performing Employee Each Month SQL | Dataford Interview Questions

Paytm Operations needs a monthly leaderboard of employees based on completed sales processed through active Paytm channels. Write a PostgreSQL query that identifies every employee who ranked first each calendar month.

Requirements

Consider only sales with sale_status = 'completed' and an active channel.
Aggregate sale_amount by employee and month using the sale date.
Use a ranking window function so employees tied for the highest monthly total are all returned.
Return the month as YYYY-MM, employee details, and the total sales amount, ordered chronologically and then by employee ID.

Schema

employees

Column	Type	Description
employee_idPK	INTEGER	Unique employee identifier
employee_name	VARCHAR(100)	Employee's full name
team	VARCHAR(100)	Operations team assigned to the employee

sales

Column	Type	Description
sale_idPK	INTEGER	Unique sale identifier
employee_id	INTEGER	Employee who handled the sale
channel_id	INTEGER	Paytm channel used for the sale
sale_date	DATE	Date on which the sale was recorded
sale_amount	NUMERIC(12,2)	Sale amount in rupees
sale_status	VARCHAR(20)	Processing status of the sale

sales_channels

Column	Type	Description
channel_idPK	INTEGER	Unique Paytm channel identifier
channel_name	VARCHAR(100)	Name of the Paytm sales channel
is_active	BOOLEAN	Whether the channel is active

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