This directory contains complete solutions for all the exercises in the SQL learning course.

Solutions Available

Basic SQL Queries

  • File: solution_01_basic_queries.sql
  • Covers: SELECT, WHERE, ORDER BY, LIMIT, aggregate functions, INSERT, UPDATE, DELETE
  • Difficulty: Beginner

JOIN Operations

  • File: solution_02_joins.sql
  • Covers: INNER JOIN, LEFT JOIN, RIGHT JOIN, CROSS JOIN, Self JOINs, complex queries
  • Difficulty: Intermediate

How to Use Solutions

  1. Try First: Always attempt the exercises yourself before looking at solutions
  2. Compare: Compare your solutions with the provided ones
  3. Learn: Understand different approaches and optimizations
  4. Practice: Modify the solutions and experiment with variations

Solution Features

  • Comprehensive: Every exercise has a complete solution
  • Commented: Solutions include helpful comments
  • Optimized: Uses best practices and efficient queries
  • Educational: Shows multiple approaches where applicable

Testing Solutions

To test the solutions:

  1. Set up the database using setup_database.sql
  2. Load sample data using sample_data/sample_data.sql
  3. Run the solutions against your database
  4. Verify results match expected outcomes

Learning Tips

  • Understand the logic: Don't just copy, understand why each query works
  • Experiment: Try modifying the solutions to see what happens
  • Performance: Consider how queries perform with larger datasets
  • Best practices: Notice the formatting and structure of the solutions

Happy learning! 🎓