Class X - Database Management

Database Management System (DBMS)

CBSE Class 10 - Information Technology (Code 402)

1. Data and Information

Data are raw facts such as numbers or words. Example: "25, 45, आयुष". By themselves, they do not hold any meaning.

Information is obtained when data is processed, organized, and given context. It becomes meaningful for decision‑making.

Scenario: The number "42" is simply data. If presented as "Marks = 42", it becomes information.

2. Database Management System (DBMS)

A database is an organized collection of data stored electronically. A DBMS is software that helps create, manage, store, update, and retrieve data efficiently.

Benefits of DBMS

• Reduces Data Redundancy: Avoids duplicate copies of the same information.
• Ensures Data Consistency: Updates appear everywhere automatically.
  Scenario: Changing "Ansh" to "Anshika" updates all records instantly.
• Data Integrity: Rules ensure data accuracy (e.g., age > 0).
• Data Sharing: Multiple users can access data with proper authorization.
• Security: Username‑password protection ensures privacy.
• Easy Search & Update: Large data can be retrieved quickly.
• Backup & Recovery: Automatic data recovery on system failure.
• Report Generation: Well‑structured printable formats.

3. Relational Database Management System (RDBMS)

RDBMS stores data in multiple tables linked using common fields (keys). Based on E.F. Codd's relational model.

• Stores medium to large amounts of data.
• Examples: MySQL, MS‑Access, OpenOffice Base, SQL Server.

4. Elements of a Database Table

• Table / Relation: Collection of records.
• Field / Column / Attribute: A specific category such as Name, Rollno.
• Record / Row / Tuple: A complete information set for one entity.
  Example: Rollno:1, Name: Karan, Marks:78.

5. Keys in DBMS

• Primary Key: Uniquely identifies each record; cannot be null.
  Example: AdmissionNo is ideal PK.
• Composite Key: Two or more fields used together as a key.
• Foreign Key: Field that links two tables.

6. Creating a Database (LibreOffice/OpenOffice Base)

1. Open LibreOffice/OpenOffice Base.
2. Select Create a new database.
3. Click Next → Finish.
4. Save the file with .odb extension.

7. Creating Tables

A. Using Table Wizard

1. Click Tables → Use Wizard.
2. Select fields from sample tables.
3. Set data types and formats.
4. Assign Primary Key.
5. Name & Finish.

B. Using Design View

1. Click Create Table in Design View.
2. Define fields like Name (VARCHAR), Rollno (TINYINT).
3. Set field properties.
4. Assign Primary Key.
5. Save table.

8. Entering Data in a Table

Open table → Datasheet View → Enter values row-wise using Tab to navigate.

Example: ID 1, Name: Ravi Kaul, Rollno 23, DOB 13/08/99, Location: Delhi.

9. Forms

Forms help users enter and view data easily in a structured layout.

Steps to Create a Form

1. Click Forms → Use Wizard.
2. Select fields.
3. Add subform (optional).
4. Choose layout style.
5. Select data entry mode.
6. Apply style & Finish.

10. Reports

Reports are used to print summarized data in an organized format.

Creating a Report

1. Click Reports → Use Wizard.
2. Select fields.
3. Group & Sort data.
4. Choose layout.
5. Finish.

11. Managing Data with SQL Queries

DML Commands

• SELECT: Retrieve data.
  Example: SELECT * FROM SDetails;
• WHERE: Filter data.
  Example: SELECT * FROM SDetails WHERE Color='Blue';
• ORDER BY: Sort data.
  Example: SELECT * FROM SDetails ORDER BY Rollno ASC;
• INSERT: Add record.
  Example: INSERT INTO SDetails VALUES (8,'Ranjith',67);
• UPDATE: Modify data.
  Example: UPDATE SDetails SET Location='Bhubaneswar' WHERE Rollno=14;
• DELETE: Remove record.
  Example: DELETE FROM SDetails WHERE ID=8;

Database Management System (DBMS)

Complete Beginner-Friendly Notes for CBSE/IT Students

1. Data and Information

Data refers to raw facts, values, or figures that have no direct meaning. Example: "25, 45, आयुष".

Information is processed, organized, or structured data that carries meaning and can be used for decision-making.

Scenario: The number "42" is simply data. But when written as "Marks = 42", it becomes information.

2. What is a Database and DBMS?

Database: An organized collection of data stored electronically for easy access and management.

DBMS: A software system that helps create, manage, store, and retrieve data efficiently.

3. Benefits of DBMS

• Reduces Data Redundancy: Avoids duplicate storage of data.
• Ensures Data Consistency: Any update made in one place reflects everywhere.
• Maintains Data Integrity: Ensures accuracy using rules like "age must be greater than 0".
• Allows Data Sharing: Multiple authorized users can access data.
• Provides Security: Access is controlled via usernames and passwords.
• Easy Searching & Updating: Large data can be searched and updated quickly.
• Backup & Recovery: Automatic backup to prevent data loss.
• Print Reports: Data can be presented in printable formats.

4. Relational Database Management System (RDBMS)

RDBMS stores data in tables (relations) connected using common fields.

Examples: MySQL, MS-Access, MS SQL Server, OpenOffice Base.

5. Elements of a Table

• Table: Collection of rows and columns.
• Field/Column: Category of data (Name, Roll No).
• Record/Row: A complete set of fields (e.g., Roll 1, Name Karan).

6. Keys in Databases

• Primary Key: Uniquely identifies each record.
• Composite Key: Combination of two attributes.
• Foreign Key: Links two tables using primary key of parent table.

7. Creating a Database (LibreOffice/OpenOffice Base)

1. Open LibreOffice/OpenOffice Base.
2. Select "Create a new database".
3. Click Next → Finish → Save.

8. Creating Tables

Using Table Wizard

1. Select "Use Wizard to Create Table".
2. Choose fields and data types.
3. Set Primary Key.
4. Save table.

Using Design View

1. Click "Create Table in Design View".
2. Enter Field Names and Types.
3. Assign Primary Key.
4. Save table.

9. Forms

Forms allow users to enter and view data easily.

1. Select "Use Wizard to Create Form".
2. Select fields and layout.
3. Choose style → Finish.

10. Reports

Reports help print and summarize data.

1. Use Wizard → Select Fields.
2. Apply sorting & grouping.
3. Choose layout → Finish.

11. SQL Commands & Queries

• SELECT: SELECT * FROM Students;
• WHERE: SELECT * FROM SDetails WHERE Color='Blue';
• ORDER BY: SELECT * FROM SDetails ORDER BY Rollno ASC;
• INSERT: INSERT INTO SDetails VALUES (8, 'Ranjith', 67);
• UPDATE: UPDATE SDetails SET Location='Bhubaneswar' WHERE Rollno=14;
• DELETE: DELETE FROM SDetails WHERE ID=8;