SQL for Channel Performance | Dataford Interview Questions

Explain how you would write a SQL query to identify the top-performing marketing acquisition channels based on customer conversion rates over the last quarter at Private Client Select.

Use the provided acquisition channel and lead data. A lead is converted when converted_at is not null. Return the top three ranks, including ties.

Output

One row per qualifying acquisition channel, with channel_name, total_leads, converted_leads, conversion_rate, and performance_rank.
Include only leads created during the last completed calendar quarter and channels with at least one lead.
Sort by rank, conversion rate descending, then channel name ascending.

Schema

acquisition_channels

Column	Type	Description
channel_idPK	INT	Unique acquisition channel identifier
channel_name	VARCHAR(100)	Marketing acquisition channel name

marketing_leads

Column	Type	Description
lead_idPK	INT	Unique lead identifier
channel_id	INT	Acquisition channel associated with the lead
lead_created_at	DATE	Date the lead entered the marketing funnel
converted_at	DATE	Date the lead converted to a customer

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

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Problem