Database Management System (DBMS): Uses, Components, SQL Basics

What is DBMS?

The full form of DBMS is Database Management System. It is a type of software that helps us store, manage, retrieve, and update data in an organized manner. By using a DBMS, data is stored in such a way that we don't need to manually create files or write programs repeatedly.

For example, suppose you have information about students, such as their names, roll numbers, marks, mobile numbers, and course details. If you store all this data manually in separate files, it would become very difficult to manage. This is exactly the task that a DBMS makes very easy.

Definition of DBMS

Database Management System (DBMS) is a software tool that stores data in a structured format and allows easy execution of various operations on that data, such as inserting, updating, deleting, and retrieving.

What is Data?

Data refers to any kind of information that tells us something about an object, person, event, or process. This information can exist in different forms, such as:

For example, a student's name, their age, marks obtained in an exam, their photo, or voice all these are forms of data.

Types of Data

Data is divided into three main types based on its structure:

1. Structured Data

Structured data is the type of data that is organized in the form of tables with rows and columns. This data is easy to understand and analyze.

Examples: Excel sheets, Database tables (such as MySQL, Oracle)

2. Unstructured Data

Unstructured data is the type of data that does not follow any fixed format or structure. It is difficult to analyze and requires special tools or techniques.

Examples: Email messages, Photos and images, Video files, Social media posts (such as Facebook, Instagram)

3. Semi-structured Data

Semi-structured data has some amount of structure but is not fully structured. This type of data uses tags or markup languages, which makes its analysis easier.

Examples: XML files, JSON files, HTML documents

Importance of DBMS

A Database Management System (DBMS) plays a crucial role in modern software and web applications. It allows users to store, manage and retrieve data efficiently and securely. In today's digital world, where almost every organization deals with large amounts of data, DBMS helps in organizing information systematically. With DBMS, you can:

Types of DBMS

Database Management Systems (DBMS) come in various types, classified based on the structure of the data and the way it is managed. Below is information about the main types of DBMS:

1. Hierarchical DBMS

In Hierarchical DBMS, data is organized in a tree-like structure. Each record has one parent and can have multiple children. This model is effective in handling one-to-many relationships.

Features

Example: IBM's IMS (Information Management System)

2. Network DBMS

Network DBMS is more flexible than the hierarchical model. It represents data as a graph structure and can handle many-to-many relationships. A child can have more than one parent.

Features

Example: Integrated Data Store (IDS), TurboIMAGE

3. Relational DBMS (RDBMS)

RDBMS stores data in tables called relations. Relationships between tables are established using foreign keys. It allows querying data using SQL (Structured Query Language).

Features

Examples: MySQL, Oracle, PostgreSQL, Microsoft SQL Server

4. Object-Oriented DBMS (OODBMS)

OODBMS combines object-oriented programming (OOP) and database management. Data is stored as objects, similar to programming languages like Java or C++.

Features

Examples: db4o, ObjectDB, Versant

Components of DBMS

A DBMS (Database Management System) consists of several important components that together help in securely storing, organizing, and easily managing data. Below are the key components of a DBMS:

1. Database

The database is the place where all the data is stored. Data is organized in the form of tables, rows, and columns so that it can be easily accessed and managed.

2. DBMS Software

DBMS software is a program that manages and controls the database. It provides the necessary tools to insert, delete, update, and access data.

3. Query Language

A query language is used to retrieve and manage data.

4. Users

Users of the DBMS are the people who use the system. They are mainly of three types:

Why DBMS is Used?

Database Management System (DBMS) has become an essential part of every software and application in today's digital age. It is used for several reasons, the main ones being:

1. Efficient Data Management

Every software or application contains a large amount of data, such as user details, orders, messages, etc. DBMS manages this data securely, in a structured and accessible manner, ensuring that the data remains organized and updated at all times.

2. Dynamic Software

In static software, data remains fixed, but with DBMS, you can modify the software based on user input. This makes the application more flexible and user-friendly.

3. Data Security

Data security is crucial for every software. DBMS protects data from unauthorized users through authentication and access control.

4. Multi-user Support

Multiple users can use the same database simultaneously. DBMS ensures smooth operation of data and prevents data loss or conflicts.

5. SQL Integration

Developers use SQL (Structured Query Language) to connect DBMS with their software. With SQL, data can be accessed, managed, and queried from anywhere.

Who Uses DBMS?

DBMS (Database Management System) is used by various professionals who specialize in designing, managing, and analyzing data. Below is information about DBMS users and their roles:

Where DBMS is Used?

DBMS (Database Management System) is used wherever there is a need to securely store, organize, and quickly access data. In today's digital world, the use of DBMS has become essential in almost every field. Below is a list of major areas where DBMS is commonly used:

1. Banking System

2. E-commerce Websites

3. Airline Reservation System

4. Hospital Management System

5. Educational Institutions

6. Telecommunications

7. Government Services

8. Social Media Platforms

9. Retail and Inventory Management

10. Library Management System

11. Customer Relationship Management (CRM) Systems

Popular DBMS Software

Below is a list of some major and widely used DBMS software, used for various types of applications and requirements:

1. MySQL

MySQL is an open-source relational DBMS, especially popular in web applications (like WordPress, PHP-based websites). It supports SQL queries and can efficiently handle large amounts of data.

Key Features

2. PostgreSQL

PostgreSQL is an advanced open-source RDBMS that is fully ACID-compliant. It can handle both structured and semi-structured data and supports custom data types and extensions.

Key Features

3. Oracle Database

Oracle is an enterprise-level RDBMS used by large businesses and organizations. It offers advanced security, backup, and recovery features.

Key Features

4. Microsoft SQL Server

Developed by Microsoft, this proprietary RDBMS is designed specifically for the Windows platform. It supports T-SQL language and integrates well with Business Intelligence (BI) tools.

Key Features

5. SQLite

SQLite is a lightweight, file-based DBMS primarily used in mobile applications (like Android) and small projects. It is serverless and requires no installation.

Key Features

6. MongoDB (Non-relational / NoSQL DBMS)

MongoDB is a NoSQL database that works on a document-oriented model. It stores data in JSON-like structures and is known for scalability and flexibility.

Key Features

7. MariaDB

MariaDB is an open-source fork of MySQL developed by the community. It offers better performance and additional features compared to MySQL.

Key Features

8. IBM Db2

IBM Db2 is a powerful enterprise DBMS designed to meet large-scale business needs. It can handle structured, XML, and JSON data.

Key Features

How Does DBMS Store Data?

DBMS (Database Management System) uses tables to store data. Each table contains multiple rows and columns, where data is organized and stored in a structured format (rows and columns). SQL is used in DBMS to store and manage the data.

What is SQL?

SQL (Structured Query Language) is a standard programming language used to access, manage, and modify data in a database. SQL is used in almost every relational database management system (RDBMS) such as MySQL, Oracle, PostgreSQL, SQL Server, etc.

Full form of SQL?

The full form of SQL is Structured Query Language. It is a declarative language, meaning you specify what to do, not how to do it.

Just like we communicate in languages like Hindi or English, when we interact with databases, we use the SQL language.

What does SQL do?

Types of SQL Commands

SQL has many important categories that are used for different tasks. These are also known as types of SQL commands.

1. Data Definition Language (DDL)

Data Definition Language is used to create, modify, and delete the structure of the database. It helps in creating or modifying tables, schemas, views, indexes, etc. DDL commands work only on the structure, not on the data. Their effects are immediate and cannot be undone.

1. CREATE

Creates a table or database object.

Example:

CREATE TABLE students (id INT, name VARCHAR(50));

2. ALTER

Adds a new column, deletes a column, or changes the datatype in a table.

Example:

ALTER TABLE students ADD age INT;

3. DROP

Permanently deletes a table or object (both data and structure).

Example:

DROP TABLE students;

4. TRUNCATE

Removes all data from a table, but the table structure remains intact.

Example:

TRUNCATE TABLE students;

2. Data Manipulation Language (DML)

Data Manipulation Language is used to insert, update, and delete data within tables. In DML, we do not change the structure of the table; we only work with the data present in the rows.

1. INSERT

Adds new data into the table.

Example:

INSERT INTO students (id, name) VALUES (1, 'Ravi');

2. UPDATE

Modifies existing data.

Example:

UPDATE students SET name = 'Amit' WHERE id = 1;

3. DELETE

Deletes data from the table.

Example:

DELETE FROM students WHERE id = 1;

3. Data Query Language (DQL)

Data Query Language is used to query and retrieve (read) data from a table. The main and only command in this category is SELECT.

SELECT

Used to read data from a table.

Example:

SELECT * FROM students;

4. Data Control Language (DCL)

Data Control Language is used for access control in the database, i.e., to determine what permissions a user will have (such as read, write, delete) and to revoke permissions from users.

1. GRANT

Grants permission to a user (for example, SELECT, INSERT).

Example:

GRANT SELECT ON students TO user1;

2. REVOKE

Revokes permissions previously given to a user.

Example:

REVOKE SELECT ON students FROM user1;

5. Transaction Control Language (TCL)

Transaction Control Language is used to manage database transactions. When you perform one or more DML operations (INSERT, UPDATE, DELETE), TCL commands ensure that the changes are safe and consistent.

1. COMMIT

Permanently saves the changes made during the transaction.

Example:

COMMIT;

2. ROLLBACK

Reverts the changes made during the current transaction (back to the last commit).

Example:

ROLLBACK;

3. SAVEPOINT

Sets a temporary point to which you can roll back.

Example:

SAVEPOINT sp1;

4. SET TRANSACTION

Sets the isolation level for a transaction (used in advanced scenarios).

Example:

SET TRANSACTION ISOLATION LEVEL READ COMMITTED;

What do beginners learn from DBMS?

DBMS (Database Management System) is a technical skill where beginners need to understand several basic but important concepts. Below is what beginners typically learn when starting with DBMS:

1. Creating a Database

The very first and essential part of DBMS is creating a database. Beginners first learn how to prepare a new database for a project or application. This is done using the SQL command CREATE DATABASE to create a named database.

Example:

CREATE DATABASE SchoolDB;

2. Creating Tables

Tables are created within the database to store data. Beginners learn about column types (such as INT, VARCHAR, DATE, etc.) and how to define relationships between them.

CREATE TABLE Students (
   StudentID INT PRIMARY KEY,
   Name VARCHAR(100),
   Age INT,
   Class VARCHAR(10)
);

3. Inserting Data

After creating the table, beginners learn how to add data into it. This is one of the most common and essential SQL commands.

INSERT INTO Students (StudentID, Name, Age, Class)
VALUES (1, 'Rahul Sharma', 15, '10A');

4. Retrieving Data

Retrieving data using the SELECT query is one of the most important activities in DBMS. It allows you to extract any information from the table.

SELECT * FROM Students;

DBMS FAQ