SQL for Data Science

What Will You Learn?

• Understand relational databases and why SQL is critical for data jobs.
• Install and connect to MySQL and run basic SQL commands confidently.
• Create and manage tables, constraints, and schema using DDL.
• Insert, update, and delete data using DML with transaction safety.
• Retrieve and filter data with SELECT, WHERE, ORDER BY, and LIMIT.
• Aggregate and summarize data using GROUP BY, HAVING, and aggregate functions.
• Combine multiple tables with INNER, LEFT, RIGHT, and FULL joins.
• Write subqueries, use EXISTS/NOT EXISTS, and create reusable views.
• Use indexes and EXPLAIN to optimize query performance.
• Normalize schemas (1NF → 3NF) and know when to denormalize.
• Use window functions (ROW_NUMBER, RANK) for advanced analytics.
• Prepare SQL outputs for dashboards and feature engineering in ML workflows.
• Apply SQL to a real e-commerce case study: monthly sales, LTV, top products.
• Build a portfolio-ready mini-project and SQL scripts for interviews.