🗃️ Unit 3: Database Management System – Class 10 Computer Applications

🗃️ Unit 3: Database Management System – Class 10 Computer Applications

📘 Introduction

A Database Management System (DBMS) is a software that allows users to store, manage, retrieve, and manipulate data efficiently. In the digital age, from school records to online banking and mobile apps, databases form the backbone of information systems. This unit introduces you to the world of databases—how to organize data in tables, run queries, create forms and reports, and build relationships between data fields.Database Management System Class 10

Let’s explore how DBMS helps in organizing and handling large volumes of data with ease and accuracy.

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🔍 3.1 Introduction to Database and DBMS

🔹 What is a Database?

A database is an organized collection of related data that can be easily accessed, managed, and updated.

Examples:

• Student records in a school
• Customer information in a bank
• Product details in an online store

🔹 What is DBMS?

A Database Management System (DBMS) is software that helps users create and maintain a database.

Popular DBMS tools:

• LibreOffice Base
• MS Access
• MySQL
• Oracle
• SQLite

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📂 3.2 Basic Concepts of Database

🔹 Data, Field, Record, Table

Term	Description	Example
Data	Raw facts or values	“John”, 15, “10th Grade”
Field	A column in a table representing a data item	Name, Age
Record	A row in the table that stores one complete set of related data	John, 15, 10th Grade
Table	A collection of related records	Student table with fields: Name, Age, Class

🔹 Field Types

Each field in a table must have a data type.

Data Type	Description	Example
Text	Alphanumeric characters	“Delhi”, “A101”
Number	Numeric values	50, 100.25
Date/Time	Dates and times	01/01/2025
Boolean	True or False	Yes/No

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🏗️ 3.3 Creating a Database and Table

🔹 Steps to Create a Database in LibreOffice Base

1. Open LibreOffice Base.
2. Select Create a new database.
3. Choose to register the database and click Finish.
4. Save the file with .odb extension.

🔹 Creating a Table

You can create a table in two ways:

• Design View: Manually define field names and types.
• Using Wizard: Choose from predefined templates.

🔸 Fields to Define:

• Field Name (e.g., Name, RollNo)
• Field Type (Text, Number, etc.)
• Field Properties (Length, Default value, Required, etc.)

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🔑 3.4 Primary Key

A primary key is a field (or a combination of fields) that uniquely identifies each record in a table.

🔹 Why Primary Key?

• Prevents duplicate records
• Helps link tables in relationships

Example: In a student table, “Roll Number” can be a primary key because it’s unique for each student.

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🧠 3.5 Relationships Between Tables

When a database contains multiple related tables, we use relationships to connect them.

🔹 Types of Relationships

1. One-to-One (1:1)
   Example: Each student has one unique ID card.
2. One-to-Many (1:N)
   Example: One teacher teaches many students.
3. Many-to-Many (M:N)
   Example: Students can enroll in many courses, and courses can have many students.

🔹 Foreign Key

A foreign key is a field in one table that links to the primary key of another table.

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🔍 3.6 Creating Queries

🔹 What is a Query?

A query is a request to retrieve or modify data from one or more tables.

🔹 Types of Queries

Query Type	Function
Select Query	Retrieves data
Action Query	Inserts, updates, or deletes data
Parameter Query	Asks user input at runtime
Cross-tab Query	Summarizes data like pivot tables

🔹 Creating a Select Query (LibreOffice Base)

1. Go to Queries > Create Query in Design View.
2. Add a table.
3. Select fields to include.
4. Set criteria (e.g., “Marks > 60”).
5. Click Run (lightning bolt icon).

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🧾 3.7 Forms and Reports

🔹 Forms

Forms are used for data entry and editing in a user-friendly interface.

Steps:

1. Go to Forms > Create Form Wizard.
2. Select the table or query.
3. Add desired fields.
4. Choose layout and style.
5. Save and open the form.

Advantages:

• Easy data entry
• Error-free input
• Guided format

🔹 Reports

Reports are used to present data in printable format.

Steps:

1. Go to Reports > Create Report Wizard.
2. Choose data source (table/query).
3. Arrange fields and group data.
4. Customize layout and design.
5. Preview and print.

Uses:

• Progress reports
• Sales summaries
• Invoice generation

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🧠 Summary Table

Feature	Purpose	Tool in DBMS
Tables	Store structured data	Table View
Primary Key	Uniquely identify records	Table Design
Relationships	Link related tables	Relationship Window
Queries	Extract specific data	Query Wizard/Design
Forms	User-friendly data entry	Form Wizard
Reports	Printable summaries	Report Wizard

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📝 Practice Questions

🔸 Short Answer

1. Define a database and give two examples.
2. What is the difference between a field and a record?
3. Explain the purpose of a primary key.

🔸 Long Answer

1. Describe how to create a table using Design View.
2. Explain different types of relationships in a DBMS.
3. Describe the steps to create a form and report in LibreOffice Base.

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🎯 Multiple Choice Questions (MCQs)

1. Which of the following is a DBMS?
   a) MS Word
   b) LibreOffice Base
   c) Photoshop
   d) Chrome
   ✅ Answer: b)
2. What is used to uniquely identify each record?
   a) Foreign Key
   b) Row ID
   c) Primary Key
   d) Header
   ✅ Answer: c)
3. Which data type is used to store numbers?
   a) Text
   b) Boolean
   c) Number
   d) Date
   ✅ Answer: c)
4. What is the purpose of a query?
   a) Store data
   b) Print data
   c) Retrieve data
   d) Edit layout
   ✅ Answer: c)
5. In a one-to-many relationship, which is true?
   a) One record is linked to one record
   b) Many records are linked to one
   c) One record is linked to many records
   d) All records are the same
   ✅ Answer: c)

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📚 Real-Life Application Examples

• School: Database of student attendance and marks
• Hospital: Patient medical history system
• Business: Inventory management and billing
• Banking: Account details and transaction history

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🧠 Conclusion

Databases are essential tools in the modern world for handling and organizing information in a structured way. In this unit, we’ve learned how to use DBMS software like LibreOffice Base to create tables, set primary keys, link tables through relationships, generate queries for data analysis, and build forms and reports for user interaction and presentation.

therefore By understanding how to work with a DBMS, you’re not only preparing for exams—you’re learning a powerful digital skill that will benefit you in almost every field.

Unit 3: Database Management System – Class 10 Computer Applications