PixoQuest
Interactive lessons and quizzes across many subjects.
SQL is the language of data. Whether you are a student, a data analyst, or a developer, the ability to ask a database questions is one of the most transferable skills in tech. This course teaches Structured Query Language from absolute zero: what a database is, how tables and rows relate, and how to retrieve exactly the data you need.
You will work through the four core operations — SELECT, INSERT, UPDATE, DELETE — and the query patterns used every day: filtering with WHERE, sorting with ORDER BY, grouping with GROUP BY, joining tables, and combining conditions with AND and OR. Every lesson pairs a concept with a quiz question, so you apply each keyword before moving on.
By the end you will be able to read and write real SQL queries, understand how joins connect relational tables, and know why indexes make queries fast. No database software is required — everything is explained with example tables you can reason about. The exercises build on each other, so the queries you write in chapter three prepare you for the joins and aggregations of chapters six and seven.
This course is built for complete beginners — no prior database or programming experience is needed. The lessons assume nothing, so you can start with zero knowledge and still keep up from the very first chapter. It also works well as a refresher for students in computer science, data science, or any course that assumes SQL.
Understand what databases and SQL are, learn the structure of relational databases, tables rows columns, primary keys, and write your very first SQL query.
Master the SELECT statement to retrieve data from tables. Learn to choose specific columns, use aliases, eliminate duplicates with DISTINCT, and limit results.
Use WHERE to filter rows with comparison operators, AND/OR/NOT, IN, BETWEEN, LIKE, and handle NULLs. Then order results with ORDER BY and paginate with LIMIT and OFFSET.
Learn SQL functions like COUNT, SUM, AVG, MIN, MAX, and string/date functions. Then group data with GROUP BY and filter groups using HAVING.
Add new data with INSERT, change existing data with UPDATE, and remove data with DELETE. Learn safe modification practices and avoid common mistakes.
Explore why databases use multiple tables, understand one-to-one, one-to-many, and many-to-many relationships, then combine tables with INNER JOIN and LEFT JOIN.
Apply everything you've learned to solve realistic business problems: find top products, inactive users, above-average scores, revenue calculations, and more.
Put your skills to the ultimate test! Restore a broken analytics dashboard in a real e-commerce database, then complete a comprehensive assessment covering all SQL topics.
No. All lessons use example tables built into the quizzes, so you learn the syntax and logic before you ever touch a real server.
Excel stores a single spreadsheet with manual formulas; SQL runs on databases that can hold millions of rows, answer questions with one query, and be updated by many users at once. This course teaches the query side.
Standard SQL — the same syntax used by PostgreSQL, MySQL, and SQLite. What you learn transfers directly to any relational database.
Around 8–10 hours of quiz-based practice, or about 25 minutes a day over three weeks. Chapters are short and each one ends with a review.
Sign in to start learning and track your progress through this course with XP, streaks, and interactive quizzes.