Introduction of MySQL

MySQL is a database management system.

What is MySQL?

MySQL is a database management system.

MySQL, the most popular Open Source SQL database management system, is developed, distributed, and supported by Oracle Corporation.

Original development of MySQL by Widenius and Axmark began in 1994.

Features of MySQL

• Easy to use
• It is secure
• Client/Server architecture
• Free to download
• It is scalable
• Speed
• High Flexibility
• Compatible on many operating systems
• Allows roll-back
• Memory efficiency
• High Performance
• High Productivity
• Platform Independent
• Partitioning
• GUI Support
• Dual Password Support

Who Uses MySQL?

• Huge websites like Facebook, Twitter, Airbnb, Booking.com, Uber, GitHub, YouTube, etc.
• Content Management Systems like WordPress, Drupal, Joomla!, Contao, etc.
• A very large number of web developers around the world

Show Data On Your Web Site

To build a web site that shows data from a database, you will need:

• An RDBMS database program (like MySQL)
• A server-side scripting language, like PHP
• To use SQL to get the data you want
• To use HTML / CSS to style the page

What is RDBMS?

• RDBMS stands for Relational Database Management System.
• RDBMS is a program used to maintain a relational database.
• RDBMS is the basis for all modern database systems such as MySQL, Microsoft SQL Server, Oracle, and Microsoft Access.
• RDBMS uses SQL queries to access the data in the database.

What is a Database Table?

A table is a collection of related data entries, and it consists of columns and rows.
A column holds specific information about every record in the table.
A record (or row) is each individual entry that exists in a table.

Types of MySQL Commands

There are five types of MySQL commands: DDL, DML, DCL, TCL, and DQL.

Data Definition Language (DDL)

DDL changes the structure of the table like creating a table, deleting a table, altering a table, etc.
All the command of DDL are auto-committed that means it permanently save all the changes in the database.

Here are some commands that come under DDL:

• CREATE
• ALTER
• DROP
• TRUNCATE

Data Manipulation Language (DML)

DML commands are used to modify the database. It is responsible for all form of changes in the database.
The command of DML is not auto-committed that means it can't permanently save all the changes in the database. They can be rollback.

Here are some commands that come under DML:

• INSERT
• UPDATE
• DELETE

Data Control Language (DCL)

DCL commands are used to grant and take back authority from any database user.

Here are some commands that come under DCL:

• Grant
• Revoke

Transaction Control Language (TCL)

TCL commands can only use with DML commands like INSERT, DELETE and UPDATE only.

These operations are automatically committed in the database that's why they cannot be used while creating tables or dropping them.

Here are some commands that come under TCL:

• COMMIT
• ROLLBACK
• SAVEPOINT

Data Query Language (DQL)

DQL is used to fetch the data from the database.

It uses only one command.

• select

The Most Important MySQL Commands

• SELECT - extracts data from a database
• UPDATE - updates data in a database
• DELETE - deletes data from a database
• INSERT INTO - inserts new data into a database
• CREATE DATABASE - creates a new database
• ALTER DATABASE - modifies a database
• CREATE TABLE - creates a new table
• ALTER TABLE - modifies a table
• DROP TABLE - deletes a table
• CREATE INDEX - creates an index (search key)
• DROP INDEX - deletes an index