NCERT SOLUTIONS
Information Technology (402)
Class – X
Unit 3: Database Management
System using LibreOffice Base
Chapter 8. Introduction to Database Management System
Important Notes of DBMS
- Data and Information
• Data: Raw, unprocessed facts and figures
without context (e.g., numbers, text, dates).
• Information: Processed data that is meaningful
and useful for decision-making (e.g., a report
showing sales trends).
Databases and DBMS
• Database: A structured collection of data
stored electronically.
• DBMS (Database Management System):
Software that manages databases and provides
tools for data entry, querying, and management
(e.g., MySQL, PostgreSQL).
,Advantages of Databases
• Data Integrity: Ensures accuracy and consistency
of data.
• Data Security: Controls access and protects
data from unauthorized access.
• Data Redundancy: Reduces duplication of data
by centralizing storage.
• Efficient Data Management: Facilitates easy
data retrieval and manipulation.
• Scalability: Can handle growing amounts of data.
Data Models
• Hierarchical Data Model
o Structure: Tree-like structure with parent-
child relationships.
o Use Case: Suitable for applications with a
clear hierarchical relationship (e.g.,
organizational charts).
• Network Data Model
o Structure: Graph-like structure with
multiple parent and child relationships.
o Use Case: Useful for complex relationships
where data entities have multiple connections
(e.g., telecommunications networks).
• Relational Data Model
o Structure: Data is organized into tables
(relations) with rows and columns.
, o Use Case: Most commonly used model, allows
for flexible queries and data manipulation.
Relational Database Model (RDBMS)
• RDBMS (Relational Database Management System)
o Definition: A type of DBMS that uses
a relational model to manage data.
o Features: Supports SQL (Structured
Query Language), enforces data integrity
through constraints.
Terminology
• Fields: Columns in a table that represent attributes
or properties of data (e.g., name, date of birth).
• Records: Rows in a table representing individual
instances of data (e.g., one person's information).
• Tables: Collections of related fields and records that
form the basic structure of a relational database.
Prepare a Sample Table
• Example Table: Employees
o Fields: EmployeeID, FirstName,
LastName, Position, HireDate
o Sample Record: (1, John, Doe,
Developer, 2024-01-15)
Different Types of Keys
• Primary Key: Unique identifier for a record in a
table (e.g., EmployeeID in the Employees table).
, • Foreign Key: A field in one table that
uniquely identifies a row of another table,
establishing relationships between tables.
Objects of RDBMS
• Tables: Store data in rows and columns.
• Queries: Requests for data retrieval or
manipulation (e.g., SELECT statements).
• Forms: Interfaces for entering and editing data.
• Reports: Structured outputs of data analysis
and summary.
Identifying Data and Information
• Data:
o Definition: Raw facts or figures without
context or meaning.
o Example: EmployeeID = 101, Salary = 50000
o Characteristics: Unorganized and lacks context.
• Information:
o Definition: Processed or interpreted data
that provides meaning and context.
o Example: “The average salary of employees
in the IT department is $50,000.”
o Characteristics: Organized, relevant, and
useful for decision-making.
Identify Fields, Records, and Tables
• Fields:
Information Technology (402)
Class – X
Unit 3: Database Management
System using LibreOffice Base
Chapter 8. Introduction to Database Management System
Important Notes of DBMS
- Data and Information
• Data: Raw, unprocessed facts and figures
without context (e.g., numbers, text, dates).
• Information: Processed data that is meaningful
and useful for decision-making (e.g., a report
showing sales trends).
Databases and DBMS
• Database: A structured collection of data
stored electronically.
• DBMS (Database Management System):
Software that manages databases and provides
tools for data entry, querying, and management
(e.g., MySQL, PostgreSQL).
,Advantages of Databases
• Data Integrity: Ensures accuracy and consistency
of data.
• Data Security: Controls access and protects
data from unauthorized access.
• Data Redundancy: Reduces duplication of data
by centralizing storage.
• Efficient Data Management: Facilitates easy
data retrieval and manipulation.
• Scalability: Can handle growing amounts of data.
Data Models
• Hierarchical Data Model
o Structure: Tree-like structure with parent-
child relationships.
o Use Case: Suitable for applications with a
clear hierarchical relationship (e.g.,
organizational charts).
• Network Data Model
o Structure: Graph-like structure with
multiple parent and child relationships.
o Use Case: Useful for complex relationships
where data entities have multiple connections
(e.g., telecommunications networks).
• Relational Data Model
o Structure: Data is organized into tables
(relations) with rows and columns.
, o Use Case: Most commonly used model, allows
for flexible queries and data manipulation.
Relational Database Model (RDBMS)
• RDBMS (Relational Database Management System)
o Definition: A type of DBMS that uses
a relational model to manage data.
o Features: Supports SQL (Structured
Query Language), enforces data integrity
through constraints.
Terminology
• Fields: Columns in a table that represent attributes
or properties of data (e.g., name, date of birth).
• Records: Rows in a table representing individual
instances of data (e.g., one person's information).
• Tables: Collections of related fields and records that
form the basic structure of a relational database.
Prepare a Sample Table
• Example Table: Employees
o Fields: EmployeeID, FirstName,
LastName, Position, HireDate
o Sample Record: (1, John, Doe,
Developer, 2024-01-15)
Different Types of Keys
• Primary Key: Unique identifier for a record in a
table (e.g., EmployeeID in the Employees table).
, • Foreign Key: A field in one table that
uniquely identifies a row of another table,
establishing relationships between tables.
Objects of RDBMS
• Tables: Store data in rows and columns.
• Queries: Requests for data retrieval or
manipulation (e.g., SELECT statements).
• Forms: Interfaces for entering and editing data.
• Reports: Structured outputs of data analysis
and summary.
Identifying Data and Information
• Data:
o Definition: Raw facts or figures without
context or meaning.
o Example: EmployeeID = 101, Salary = 50000
o Characteristics: Unorganized and lacks context.
• Information:
o Definition: Processed or interpreted data
that provides meaning and context.
o Example: “The average salary of employees
in the IT department is $50,000.”
o Characteristics: Organized, relevant, and
useful for decision-making.
Identify Fields, Records, and Tables
• Fields:
