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SQL for data cleaning & preprocessing
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PostgreSQL for structured data storage
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Power BI for dashboard development
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DAX for advanced analytics and KPIs
The goal of this project was to transform raw retail transaction data into a professional, interactive business intelligence dashboard that provides actionable insights into sales performance, customer behavior, and revenue trends.
The dataset was stored and managed in a PostgreSQL relational database to ensure:
Structured schema design
Efficient querying
Data consistency
Scalability for BI tools
Using SQL, the following transformations were performed:
Removed null or invalid customer IDs
Cleaned inconsistent date formats
Filtered cancelled/negative invoices
Created calculated revenue column (quantity * unit_price)
Standardized column naming conventions (lowercase schema)
Handled duplicates
Optimized data types for performance
The dashboard provides an executive-level summary of retail performance.
Total Sales: $8.9M
Total Orders: 397K
Total Customers: 4,338
Total Quantity Sold
Monthly Revenue Trend
Daily Sales Distribution
Quarter-based customer growth
Monthly distinct customers
Repeated vs One-time customers
Retention indicators
Top 3 Products by Revenue
Revenue contribution breakdown
Custom Month Button Slicer (Jan–Dec)
Dynamic KPI updates
Performance-driven visual filtering
Interactive trend visualization
Advanced DAX measures were created to power dynamic analytics:
Data cleaning & transformation
Conditional filtering
Calculated columns
Data validation
Query optimization
Schema structuring
Database creation
Table management
Data integrity handling
Relational data modeling
Data modeling
Relationship management
Date table implementation
Interactive slicers
Edit interactions
Executive KPI layout design
Visual storytelling
Aggregation functions
Time intelligence (PREVIOUSMONTH)
Context transition (CALCULATE)
FILTER logic
DIVIDE for safe calculations
Customer segmentation logic
Revenue analysis
Customer retention metrics
AOV calculation
Month-over-Month growth
KPI performance monitoring
Executive dashboard design





