CBSE 12th Unit 3-Chapter -1 DATABASE MANAGEMENT AND DATABASE CONCEPTS

 

UNIT – 3

Chapter - 1

Introduction to Database Concepts

A database is a structured collection of data organized in a way that allows for efficient storage, retrieval, and management. ¹ It's like a digital warehouse for information, enabling users to store, organize, and access data easily.  

Key Components:

• Data: Raw facts and figures (e.g., names, numbers, dates, images).
• Information: Processed and organized data that is meaningful and useful.
• Database Management System (DBMS): Software that interacts with the user, the database engine, and the application. Examples include MySQL, PostgreSQL, Oracle, and SQL Server.

Diagram: Basic Database Structure

 

database diagram showing tables, rows, columns, primary key, and foreign key

Need for Databases

• Efficient Data Storage and Retrieval:
• Stores and retrieves large volumes of data quickly.
• Enables easy searching and filtering of data.
• Data Integrity and Consistency:
• Ensures data accuracy and consistency across the system.
• Reduces redundancy and errors.
• Data Security:
• Provides mechanisms to control access and protect data from unauthorized use.
• Data Sharing and Collaboration:
• Allows multiple users to access and share the same data simultaneously.
• Data Analysis and Decision Making:
• Enables data analysis and reporting to support business decisions.

Example: Student Database

Let's consider a simple student database.

Table: Students

Column Name	Data Type	Description
StudentID	INT	Unique identifier for each student (Primary Key)
FirstName	VARCHAR(50)	First name of the student
LastName	VARCHAR(50)	Last name of the student
Age	INT	Age of the student
Class	VARCHAR(20)	Class of the student (e.g., "10th Grade")

Export to Sheets

Code Example (SQL - Structured Query Language)

SQL

-- Create the Students table

CREATE TABLE Students (

    StudentID INT PRIMARY KEY,

    FirstName VARCHAR(50),

    LastName VARCHAR(50),

    Age INT,

    Class VARCHAR(20)

);

 

-- Insert data into the table

INSERT INTO Students (StudentID, FirstName, LastName, Age, Class)

VALUES

    (1, 'John', 'Doe', 15, '10th Grade'),

    (2, 'Jane', 'Smith', 16, '11th Grade'),

    (3, 'David', 'Lee', 14, '9th Grade');

 

-- Retrieve data from the table

SELECT * FROM Students;