As part of my practical SQL certification exam, I worked with raw product data from FoodYum – a fictional grocery retailer navigating inflation-driven consumer behavior.
The dataset had significant data quality issues and gaps that prevented business users from analyzing product availability, pricing strategies, and customer accessibility.
Clean and structure the dataset for reliable analysis
Identify missing/incomplete product records and fix them using business rules
Enable KPI tracking of product distribution, category performance, and price ranges
Support decision-making around pricing, customer segmentation, and inventory optimization
SQL-based Data Cleaning: Detected and handled nulls, removed outliers, fixed datatype mismatches
Business Logic Imputation: Median-based imputation for numeric fields, categorical fallback for types
Data Enrichment: Added derived columns for analysis (e.g., price/weight ratio, category coverage)
Exploratory SQL Queries: Filtered, grouped and ranked product performance across dimensions
Churn Risk Flagging: Used filters to highlight product types at risk of customer drop-off
This project demonstrated the importance of structured SQL logic in preparing datasets for business use.
It also confirmed that data cleaning is not just technical – it’s a strategic step that determines what the business can see, understand and act on.
Even without visual tools, SQL alone delivered powerful insight into churn risk, price positioning and SKU health.