Cast and Clean Data in SQL | Dataford Interview Questions

Microsoft Store analysts receive revenue data from multiple reporting systems, so the same value may contain currency symbols, commas, whitespace, or invalid text. Write a PostgreSQL query to prepare the revenue column for analysis.

Requirements

Clean raw_revenue by removing currency symbols, commas, and surrounding whitespace, then cast valid values to NUMERIC(12,2).
Return every sale, using NULL for missing or invalid revenue values, and order the results by sale_id.

Schema

store_sales

Column	Type	Description
sale_idPK	INTEGER	Unique sale identifier
product_name	VARCHAR(100)	Microsoft Store product name
raw_revenue	VARCHAR(30)	Revenue received as unprocessed text

Your question is Cast and Clean Data in SQL. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Requirements

Clean raw_revenue by removing currency symbols, commas, and surrounding whitespace, then cast valid values to NUMERIC(12,2).
Return every sale, using NULL for missing or invalid revenue values, and order the results by sale_id.

Schema

store_sales

Column	Type	Description
sale_idPK	INTEGER	Unique sale identifier
product_name	VARCHAR(100)	Microsoft Store product name
raw_revenue	VARCHAR(30)	Revenue received as unprocessed text

Your question is Cast and Clean Data in SQL. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.