Relearning SQL Through Real-World E-Commerce Projects
Sharing my journey relearning SQL by working on real e-commerce projects using MySQL and PostgreSQL, focusing on practical business-driven queries.
I want to share my experience of relearning SQL, which I am currently diving back into.
This started because my current project is closely related to SQL, specifically an e-commerce platform. The backend stack uses MySQL with Laravel, and in some parts PostgreSQL as well. Because of that, I became interested in revisiting SQL fundamentals and sharpening my skills again.
To rebuild a solid foundation, I decided to study through DataCamp and completed the following courses:
Introduction to SQL
https://www.datacamp.com/completed/statement-of-accomplishment/course/2a5b95c3d50b83f77f051cbd99e0c10400d65458Introduction to SQL Server
https://www.datacamp.com/completed/statement-of-accomplishment/course/a115bdd43fa73424e6a572e71cc3c1261ab649b0Intermediate SQL Server
https://www.datacamp.com/completed/statement-of-accomplishment/course/ca7b3bed05e7b9e4404553adbb830d75b3c87317
Previously, I worked as a data engineer for several years before taking a step back to explore different technical directions.
At the moment, I am learning SQL through more realistic and business-driven queries that reflect real workflows. Since my focus is e-commerce, I am exploring how to design and query data related to products, transactions, users, admins, categories, inventory stock, pricing, shipping processes, invoices, payments, and many other related tables.
The goal is not just to write SQL queries, but to truly understand how data flows in a real production system.
Below are several SQL and database technologies that I have worked with:
MySQL
Well-suited for Laravel/PHP stacks, startups (mid-scale), and CRUD-heavy applications.
MySQL Pros
Simple and stable
Widely supported by hosting providers
Affordable and easy to maintain
MySQL Cons
Complex queries can become expensive
Advanced SQL features matured relatively late
MySQL E-commerce use cases
Products
Orders
Users
Payments
PostgreSQL
Well-suited for B2B e-commerce, systems with complex queries, and hybrid OLTP + analytics workloads.
PostgreSQL Pros
Rich and strict SQL implementation
Powerful features such as window functions, CTEs, and JSONB
Excellent for reporting and analytics with strong data integrity
PostgreSQL Cons
More complex setup and tuning
Hosting is relatively more expensive
Requires strong schema discipline
PostgreSQL E-commerce use cases
Pricing rules
Contract-based pricing
Inventory movements
Invoices and financial reports
Shipment analytics
SQL Server
Well-suited for enterprise B2B systems, finance, ERP, internal platforms, and BI/data engineering teams.
SQL Server Pros
Strong tooling (SSMS, reporting services)
Stable and reliable performance
Excellent support for ETL and BI workflows (SSIS)
Strong support for stored procedures and views
SQL Server Cons
Expensive licensing
Rarely used in startup environments
Less flexible compared to PostgreSQL
SQL Server E-commerce use cases
Data warehouses
Financial reporting
Sales dashboards
Audit and compliance systems
NoSQL
Best used as a complementary technology rather than a replacement for SQL databases.
NoSQL E-commerce use cases
Shopping carts
User sessions
Product view caching
Activity logs
Search indexing
If you are building or scaling an e-commerce system—especially B2B—and need help with database design, SQL optimization, or data modeling based on real business workflows, feel free to reach out.
You can contact me via email at hello@farros.co.