Welcome to my SQL Projects Portfolio, a collection of real-world data analysis projects powered by SQL and exploratory data tools. These projects demonstrate my ability to translate business questions into data-driven insights using relational databases, advanced querying, and visualization.

• SQL Engines: PostgreSQL, SQLite
• Languages: SQL, Python (for visualization and notebooks)
• Libraries: pandas, matplotlib, seaborn
• Concepts: Joins, Aggregations, CTEs, Window Functions, Subqueries, Database Design, ERD
• Other: Jupyter Notebooks, Data Cleaning, Statistical Analysis, Problem Solving

Each folder contains a self-contained project with relevant scripts, data, and notebooks.

Explore which countries owe the most debt and to whom using debt statistics from the World Bank.

Skills: SQL joins, aggregation, filtering, global data analysis.

Use SQL to explore baby name popularity over the decades in the U.S.

Skills: CTEs, window functions, time-based analysis, trend detection.

Study EV charging patterns to uncover usage trends and station performance.

Skills: Grouping, average duration analysis, behavior patterns.

Investigate which sectors contribute most to pollution and how emission levels change.

Skills: Grouping by sector, subqueries, cumulative comparisons.

Analyze a dataset of motorcycle parts to determine top products, revenue drivers, and trends.

Skills: Transactional analysis, revenue computation, rank functions.

Examine survey data to understand mental health challenges faced by students.

Skills: Conditional logic, percentage breakdowns, demographic filters.

Explore TfL (Transport for London) subway data to uncover peak travel times and busiest lines.

Skills: Multi-table joins, ridership analysis, daily trends.

Assess the effectiveness of an NGO’s social campaigns using project and impact data.

Skills: ERD interpretation, relational schema analysis, data summarization.

• Comfort with relational database structure and logic
• Advanced SQL for business analysis and insight generation
• Real-world datasets and practical case studies
• Communication of complex data insights through visual and narrative storytelling

If you’re hiring or collaborating on data-centric projects, I’d love to chat. Feel free to reach out!

📧 joaquinrojash@hotmail.com
🌐 LinkedIn
🐙 GitHub Profile