Start learning SQL

SQL is the standard computer language for accessing and processing databases.

Examples of each chapter

Each chapter provides a simple example of SQL.

Start learning SQL!

SQL queries select all records from the user table:

SELECT * FROM users;

SQL queries remove a single record from a user table by using the where clause:

DELETE FROM users WHERE user_id=299;

Suitable for people

The purpose of this reference is to help beginners learn SQL languages in depth.

SQL quiz test

Test your SQL skills at w3cschool!

Start the SQL quiz!

SQL Quick Reference

An SQL quick reference. Print and put it in your pocket.

SQL Quick Reference

SQL data type

Data types and scopes for Microsoft Access, MySQL, and SQL Server.

SQL data type

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Learning prerequisites

This reference prepares a variety of examples, and before you officially begin the exercise, I assume that you already know what a database is, especially a relationship database management system (RDBMS), and what a computer programming language is.