MySQL - Introduction
Introduction
A database is a collection of organized and structured data that is stored and managed on a computer system. It is designed to enable efficient and easy access, retrieval, modification, and deletion of data. Databases are widely used in various applications, such as websites, mobile apps, business systems, and many more.
DBMS stands for Database Management System, which is a software system that enables users to define, create, maintain, and control access to a database. RDBMS stands for Relational Database Management System, which is a type of DBMS that stores and organizes data in the form of tables and provides a means of retrieving data based on logical relationships between tables.
A relational database management system (RDBMS) is a type of DBMS that is based on the relational model, introduced by E.F. Codd in 1970. It organizes data into tables, where each table represents a relation, and each row in the table represents a record. The RDBMS uses SQL (Structured Query Language) to manipulate the data stored in the tables.
MySQL is a popular open-source RDBMS that was introduced in 1995 by MySQL AB, a Swedish company founded by Michael Widenius and David Axmark. It was later acquired by Sun Microsystems in 2008, and then by Oracle Corporation in 2010. MySQL is widely used in various applications, such as web applications, content management systems, and online forums. It is supported on various platforms, including Windows, Linux, and macOS. MySQL is known for its ease of use, scalability, and reliability.
MySQL was developed to be a cross-platform RDBMS that could run on various operating systems such as Linux, Windows, and macOS. It was developed using the C and C++ programming languages and is licensed under the GNU General Public License.
MySQL became popular due to its simplicity and versatility, and it is now widely used in web applications, content management systems, e-commerce platforms, and other types of software. It is estimated that MySQL is used by over 60% of websites that use a database management system.
Here's an example of an RDBMS table:
Consider a company that has multiple departments, and each department has multiple employees. We can represent this data using two tables: "departments" and "employees".
Table: Departments
|
department_id |
department_name |
|
1 |
Marketing |
|
2 |
Sales |
|
3 |
Finance |
Table: Employees
|
employee_id |
employee_name |
department_id |
|
1 |
John Doe |
1 |
|
2 |
Jane Smith |
1 |
|
3 |
Bob Johnson |
2 |
|
4 |
Sam Lee |
2 |
|
5 |
Tom Brown |
3 |
In this example, the "department_id" column in the "employees" table is a foreign key that refers to the "department_id" column in the "departments" table. This relationship helps in retrieving data about employees and their respective departments using a single query.
RDBMSs like MySQL provide features such as ACID (Atomicity, Consistency, Isolation, Durability) properties, transaction management, and referential integrity, making them suitable for managing complex data and ensuring data consistency and accuracy.
