Gwecode.
Beginner · SQL

SQL for Beginners

Learn to store and find data with SQL. Tables, queries, and safe updates explained in plain English, so your Gwecode website can remember things.

Every real website needs to remember things: users, posts, products, orders. This course teaches SQL from zero, in small steps. You will learn what a database is, how to read and write data with simple queries, how to build your own tables, and how two tables connect together. No experience needed, just curiosity.

Beginner 12 lessons ~86 min SQL
Start the course
01

Getting Started with Databases

What a database actually is, how information is organized inside one, and how to ask it your first question.

3 lessons
  1. 1 What Is a Database, and Why Does Your Website Need One? The place where your website remembers things 6 min
  2. 2 Tables, Rows, and Columns How a database organizes information 6 min
  3. 3 Your First SELECT Query Asking the database a question 7 min
02

Finding the Data You Want

Narrow results down with WHERE, control their order and count with ORDER BY and LIMIT, and add brand new rows with INSERT.

3 lessons
  1. 4 Filtering Rows with WHERE Only show me what I need 7 min
  2. 5 Sorting and Limiting Results ORDER BY and LIMIT 7 min
  3. 6 Adding New Data with INSERT Putting new rows into a table 7 min
03

Changing and Structuring Data

Update and delete existing rows safely, then design your own table by choosing sensible data types and a primary key.

3 lessons
  1. 7 Updating and Deleting Data (Carefully!) Changing what's already there 8 min
  2. 8 Creating a Table and Choosing Data Types Designing where your data will live 8 min
  3. 9 Primary Keys: Giving Every Row a Unique Identity How the database tells rows apart 7 min
04

Combining and Summarizing Data

Connect two related tables with a gentle JOIN, then turn many rows into one useful number with COUNT, SUM, and AVG.

3 lessons
  1. 10 A Gentle Introduction to JOIN Connecting two tables together 8 min
  2. 11 Counting, Summing, and Averaging with COUNT, SUM, and AVG Turning rows into answers 7 min
  3. 12 Putting It Together: How a Blog or Shop Uses These Queries SQL in real Gwecode projects 8 min