SQL: Basic
Learn SQL from scratch — SELECT queries, joins, aggregation, and updates — with interactive quizzes that check your understanding as you go.
About This Course
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.
What You'll Learn
- Explain relational database fundamentals: tables, rows, columns, and keys
- Write SELECT queries with WHERE filtering and logical operators
- Sort and limit results with ORDER BY and LIMIT
- Aggregate data with COUNT, SUM, AVG, MIN, and MAX
- Group results with GROUP BY and filter groups with HAVING
- Join two or more tables with INNER, LEFT, and RIGHT JOIN
- Insert, update, and delete rows safely
- Understand what an index is and when it speeds queries up
Who This Course Is For
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.
Full Syllabus
SQL & Databases Fundamentals
Databases, tables, rows, columns and primary keys; your first query
SELECT Basics
SELECT specific columns, aliases, DISTINCT and limiting results
Filtering & Sorting Data
WHERE, AND/OR/NOT, IN, BETWEEN, LIKE, NULLs; ORDER BY and LIMIT
Aggregating & Grouping Data
COUNT, SUM, AVG, MIN, MAX, then GROUP BY and HAVING
Modifying Data
INSERT, UPDATE and DELETE, with safe modification habits
Relationships & Joins
Why databases use several tables; INNER JOIN and LEFT JOIN
Practical SQL Challenge Lab
Real business questions: top products, inactive users, revenue
Boss Battle & Final Assessment
Restore a broken analytics dashboard, then a final assessment
Try a Worked Example
Practice SELECT and WHERE on a small sample table with a full explanation: SQL SELECT and WHERE practice. Then continue in the course to build the habit chapter by chapter.
Frequently Asked Questions
Do I need to install a database?
No. All lessons use example tables built into the quizzes, so you learn the syntax and logic before you ever touch a real server.
How is SQL different from Excel?
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.
Which database does this course teach?
Standard SQL — the same syntax used by PostgreSQL, MySQL, and SQLite. What you learn transfers directly to any relational database.
How long is the course?
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.
