SQL

Every lesson in this track uses the E-commerce schema you built in Setting Up Your DB Schema using MySQL. The examples, practice queries, and exercises all reference the same core tables so you can see how each concept fits together in a consistent dataset.

E-commerce Schema Snapshot

• category: Product categories (category_id, category_name)
• seller: Marketplace stores and contacts
• customer: Shoppers with optional category preferences
• product: Catalog of items, tied to categories and sellers
• orders: Customer purchases with status and delivery details
• order_item: Line items connecting orders to products
• transactions: Payment attempts and outcomes

Refer back to the schema lesson whenever you need DDL or seed data. Each subsequent module builds on that foundation:

• 01. Introduction to Databases and SQL
• 02. Setting Up Your SQL Environment
• 03. Basic SQL Query Structure
• 04. Filtering Data with WHERE Clause
• 05. Sorting and Limiting Results
• 06. Using Aggregate Functions
• 07. Grouping Data with GROUP BY
• 08. Filtering Groups with HAVING
• 09. Combining Tables with JOINs
• 10. Working with Subqueries
• 11. Using Common Table Expressions (CTEs)
• 12. Modifying Data with INSERT, UPDATE, DELETE
• 13. Creating and Altering Tables
• 14. Understanding Data Types and Constraints
• 15. Implementing Indexes for Performance
• 16. Working with Views
• 17. Managing Transactions
• 18. Writing Stored Procedures and Functions
• 19. Database Security and User Management
• 20. SQL Best Practices and Optimization