E-Commerce Sales, Customer Behavior & Operations Analytics (T-SQL)

An end-to-end database engineering and advanced analytics project querying 138,116+ transactions spanning 2021–2025 across a 4-table relational architecture. Built entirely in Microsoft SQL Server and SSMS, this project demonstrates production data hygiene, referential integrity enforcement, query optimization (resolving TempDB spools), and progressive business intelligence using Multi-Table Joins, Comparative Subqueries, Window Functions, Multi-Stage CTEs, and a Flagship Capstone Synthesis