SQL Introduction: Commands, Sample Table and Learning Path

SQL (Structured Query Language) is used to define database structures, add and change data, retrieve rows, control access, and manage transactions. You can learn the commands progressively rather than memorizing everything at once.

SELECT id, name, mark
FROM student
WHERE mark > 60
ORDER BY mark DESC;

This query reads selected columns from the student table, keeps rows with marks above 60, and sorts the result from highest to lowest mark.

SQL syntax is standardized, but database products add their own features and differences. These tutorials focus mainly on MySQL.

SQL basics, sample student table and first SELECT query

Show Table of Contents

Types of SQL commands
Querying data
Create the sample student table
Insert sample rows
Recommended learning path

Types of SQL Commands Top ↑

Category	Purpose	Examples
DDL	Define or change database objects.	CREATE, ALTER, DROP, RENAME, TRUNCATE
DML	Add, change or remove stored rows.	INSERT, UPDATE, DELETE
DQL	Retrieve data.	SELECT
DCL	Control privileges.	GRANT, REVOKE
TCL	Control transactions.	COMMIT, ROLLBACK, SAVEPOINT

Core Querying Topics Top ↑

Topic	What it teaches
SELECT	Retrieve columns and rows.
WHERE	Filter rows with conditions.
BETWEEN	Filter values within a range.
IN	Match against a list of values.
LIKE	Wildcard text matching.
REGEXP	Regular-expression matching.
ORDER BY	Sort result rows.
LIMIT	Restrict result-row count.
DISTINCT	Return unique result values.
GROUP BY	Group rows for summaries.
HAVING	Filter grouped results.
INNER JOIN	Combine matching rows from tables.
LEFT JOIN	Keep all rows from the left table.
UNION	Combine compatible result sets.
Subqueries	Use a query inside another query.
CASE	Conditional values in SQL.
NULL	Work with missing or unknown values.

Useful Query Functions and Expressions

As you progress, these tutorials extend the core query commands: COUNT(), MAX(), GROUP_CONCAT(), CONCAT(), REPLACE(), IF(), IS, AND / OR, LOCATE(), RAND(), and window functions with OVER().

You can manage the server through tools covered in MySQL front-end tools.

Create a Sample Student Table Top ↑

The tutorials commonly use a small student table. This modern definition uses InnoDB, a primary key and utf8mb4.

CREATE TABLE student (
    id INT UNSIGNED NOT NULL AUTO_INCREMENT,
    name VARCHAR(50) NOT NULL,
    class VARCHAR(20) NOT NULL,
    mark TINYINT UNSIGNED NOT NULL DEFAULT 0,
    PRIMARY KEY (id)
) ENGINE=InnoDB
  DEFAULT CHARSET=utf8mb4;

For a deeper explanation of columns, datatypes and constraints, continue to Tables & Records, Data Types and Primary Keys.

Insert Sample Rows Top ↑

INSERT INTO student (id, name, class, mark) VALUES
(1, 'John Deo', 'Four', 75),
(2, 'Max Ruin', 'Three', 85),
(3, 'Arnold', 'Three', 55),
(4, 'Krish Star', 'Four', 60),
(5, 'John Mike', 'Four', 60),
(6, 'Alex John', 'Five', 55);

Recommended Learning Path Top ↑

Install or access MySQL.
Create/select a database.
Understand tables and records.
Create a table and choose data types.
Insert data.
Start retrieving data with SELECT, WHERE and ORDER BY.

MySQL Installation Database Basics Tables & Records SELECT Query

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

About the author Watch on YouTube

Connect:

Subscribe to our YouTube Channel here