Free SQL Courses

SQL is the one skill on this site that shows up in almost every other track: data science, backend development, analytics, all of it eventually touches a database. Harvard CS50's Introduction to Databases with SQL is the most rigorous free option, covering both querying and database design. Khan Academy and Kaggle Learn both offer shorter, more practical introductions if you just need to write queries for a project. freeCodeCamp's Relational Database course pairs SQL with PostgreSQL in a Linux environment, which is closer to how it's actually used on the job. Google's Data Analytics certificate teaches SQL as one piece of a bigger analyst toolkit, worth considering if querying isn't your end goal on its own.