SQL · Basic to Pro

SQL & Databases — Full Course

This course takes you from your very first SELECT statement to writing the kind of SQL used by real backend and analytics teams — window functions, query performance, and transactions that keep data correct under concurrent access.

Every lesson includes runnable example queries. Try them against a free SQLite playground in your browser, or your own local database, and use the Back and Forward buttons to move through the course in the order it was designed.

What you will learn

  • Querying and filtering rows with SELECT and WHERE
  • Sorting, limiting, and removing duplicates
  • Aggregate functions and GROUP BY
  • Joining data across multiple tables with INNER JOIN and LEFT JOIN
  • Subqueries and Common Table Expressions (CTEs)
  • Basic database design: primary keys, foreign keys, and creating tables
  • Window functions for ranking and running totals
  • Indexes and reading a query execution plan
  • Transactions and constraints that protect data integrity

Who this is for

No prior programming experience required. Especially useful if you are moving into a data analyst, backend, or full-stack role where querying a database is a daily task.

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Lessons

01 Welcome to SQL: Talking to a Database 3 min read 02 SELECT, WHERE and Filtering Rows 2 min read 03 Sorting, Limiting and Removing Duplicates 2 min read 04 Aggregate Functions and GROUP BY 2 min read 05 JOINs: Combining Data From Multiple Tables 2 min read 06 Subqueries and Common Table Expressions 2 min read 07 Basic Database Design and What’s Next 2 min read 08 Window Functions 2 min read 09 Indexes and Query Performance 2 min read 10 Transactions and Data Integrity 2 min read