- Understand the Basics
Start with the fundamentals: SELECT, INSERT, UPDATE, DELETE, and basic filtering (WHERE). Learn about data types and their importance.
- Practice on Real Datasets
Use free datasets (e.g., Kaggle, public APIs) to create your own database. Practice writing queries to solve practical problems, like data analysis or reporting.
- Master Joins and Relationships
Get comfortable with INNER, LEFT, RIGHT, and FULL OUTER JOINs. Understand primary keys, foreign keys, and normalization concepts.
- Optimize Queries
Learn how to use indexes and analyze query performance. Understand the cost of operations like GROUP BY and ORDER BY.
- Explore Advanced Topics
Dive into window functions, subqueries, and CTEs (Common Table Expressions). Learn about database transactions and ACID properties.
- Use SQL Daily
Incorporate SQL into your workflow—whether through data exploration, building reports, or troubleshooting.
- Learn from Others
Join forums like Stack Overflow or SQL-specific communities. Read others' solutions to real-world problems; it’s a great way to see alternate approaches.