DBMS (MySQL)
Some popular DBMS software are: MySQL, SQLite, Oracle, SQL Server, IBM
DB2, MS-Access, etc.
Data & Information
Data is the collection of raw facts, numbers, words or other useful information.
Information refers to the data that has been processed and organized to provide
specific meaning.
Database
A database is an organized collection of data that can be easily managed and
accessed. It stores information in a structured format, often using tables. Some
examples: Dictionary, Telephone Diary, Attendance Register, Mark-Ledger etc.
Importance:
Databases play a vital role in modern computing and everyday life. Its importance
can be listed as:
a) It helps to store large amounts of data in a structured way.
b) Users can retrieve data easily and efficiently.
c) Ensures the accuracy and consistency of stored data.
d) Sensitive data can be protected with passwords.
Applications:
Databases are used in almost every field. Some real-world examples are:
Education: Student records, attendance tracking, exam results
Banking: Account details, customers records, transaction records, loan
management
Businesses: Sales and Inventory, Financial Records, Customer and staff records
Healthcare: Patient records, appointment schedules, medical billing
E-commerce: Customer orders, payment processing, product catalogs
Government: Tax records, citizen records, voter list, etc.
DBMS (Database Management System)
A DBMS is an application software that is used to store, organize, and manage
data in a database. It provides a platform for users to carry out different actions
like creating database, editing, updating, deleting and retrieving the data in a
database.
Advantages:
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Large volume of data can be stored and updated easily.
It helps to control the data redundancy.
It provides security features for protecting the database from unauthorized
access.
It provides the data sharing facility.
It ensures data integrity by allowing accurate, consistent, and validated
data.
It provides backup and recovery of databases.
Disadvantages:
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It can be expensive to setup and maintain due to requirement of software,
hardware, and skilled personnel.
Database design can be complex, requiring careful planning and
understanding.
If the database is corrupted, it can potentially affect all data stored within
it.
DBMS can be vulnerable to security breaches if it is not configured
properly. This can lead to data loss or theft.
RDBMS (Relational Database Management System)
Table
RDBMS stands for Relational Database Management System. It is a type of
software that helps to store, organize, and manage data in a structured format. In
RDBMS, tables can be linked together using special fields called keys. Some
examples: MySQL, Oracle, MS-Access etc.
It is the primary object of the database that can store large volume of the data in
the form of rows and columns. Each column in a table represents a field, while
each row represents a record.
A field is a component of a table that stores specific type of data. It is also known
as attribute.
MySQL
MySQL is a popular RDBMS software that helps to store, organize, and manage
data using tables. It uses a language called SQL (Structured Query Language) to
create, update, and manage the database.
It is open-source software developed by Oracle Corporation and was first released
in 1995.
Features of MySQL / Advantages
 It is free and open-source software.
 It is easy to understand and use.
 It is fast and reliable for handling large data.
 It can be connected with websites and applications.
 It supports multiple users at the same time.
 It can create relationships between tables.
Components of MySQL:
1. Database 2. Table
3. Row (Record)
5. Primary Key
6. Foreign Key
4. Column (Field)
A record is a set of related data that is organized in a group of fields within a
table. It is also known as tuple.
Uses of Table:
 Tables allow to store large volume of data in an organized way.
 Tables are used to create relationships between different sets of data.
 Tables are often queried to retrieve specified data based on given conditions.
Rules for writing field names in MS-Access
 Can be up to 64 characters long.
 Can include any combination of letters, numbers, spaces, and special
characters except a period (.), an exclamation point (!), an accent grave
(`), and brackets [ ].
 Can't begin with a space.
Primary key
A primary key is a special field or group of fields that uniquely identifies each
record in a table. It ensures that no two records in the table have the same value
for the primary key field(s).
Importance/Uses
 It ensures that each record in the table is unique by preventing duplicate
entries.
 It enhances the speed and efficiency of querying and retrieving records from
the database.
 It is used to establish relationships between different tables.
Data types in MS-Access:
5. Currency: The Currency data type is designed to store monetary values with
fixed number of decimal places. It uses 8 bytes of storage. This makes it ideal for
fields such as "Price", "Salary", or "Total Cost".
6. AutoNumber: The AutoNumber data type automatically generates a unique
number for each new record in a table. It is commonly used as a primary key to
uniquely identify each entry.
7. Yes/No: The Yes/No data type stores Boolean values, representing options such
as True/False or Yes/No. It uses only 1 bit of space and is useful for fields that
require a binary choice, such as "Available", "Passed", or "Subscribed".
1. Short Text: The Short Text data type is used to store alphanumeric information
such as names, addresses, or any combination of letters, numbers, and symbols.
It can hold up to 255 characters and is suitable for data that doesn't require
complex formatting or large amounts of text. It is commonly used for fields like
"Name", "City", or "Email Address".
Note: It is the default data type of a field.
2. Long Text (Memo): The Long Text, previously called Memo, allows for
storage of large blocks of alphanumeric text—up to 65,535 characters. It is ideal
for fields that require detailed descriptions, notes, or comments. Unlike Short
Text, it can include line breaks and more formatted content.
3. Number: The Number data type is used to store numeric values that are meant
for mathematical calculations. MS Access offers several subtypes: Byte, Integer,
Long Integer, Single, and Double - each varying in size and range. For example,
Byte uses 1 byte to store values from 0–255, while Double uses 8 bytes for more
precise floating-point numbers. It is best used for fields like "Age", "Quantity",
or "Marks".
4. Date/Time: The Date/Time data type stores dates and times in various formats.
It occupies 8 bytes and can be used for calendar-based data like birth dates,
appointment times, or record timestamps. Users can customize display formats,
such as "dd/mm/yyyy" or "hh:mm AM/PM".
8. OLE Object: The OLE Object data type allows a user to embed objects like
images, audio clips, videos, or Microsoft Office documents. Its size varies
depending on the embedded object, and it is commonly used when multimedia
content needs to be part of the database.
9. Hyperlink: The Hyperlink data type is used to store clickable links to websites,
files, or email addresses. It can hold up to 2048 characters and simplifies the
process of linking database records to online resources or external documents.
10. Attachment: The Attachment data type lets you attach one or more files to a
single record. These can include documents, images, spreadsheets, etc.
Attachments are stored separately in the database, keeping file size manageable
and the structure organized.
11. Lookup Wizard: The Lookup Wizard isn’t exactly a data type but a feature
that helps create a dropdown list of values from another table or a predefined
list. It simplifies data entry by allowing users to select from options, improving
accuracy and consistency in data input. It occupies 4 bytes of storage.
Summary table of datatype:
Data Type
Description / Use
Storage Size
Default
field size
Short Text
(Text)
Long Text
(Memo)
Number
Date/Time
Currency
AutoNumber
Yes/No
Stores alphanumeric data (letters,
numbers, or symbols)
Stores longer alphanumeric data for
descriptions or notes.
Stores numeric data. Can be used for
integer or decimal value.
 Byte – 1 byte (0 to 255)
 Integer – 2 bytes
 Long Integer – 4 bytes
 Single – 4 bytes
 Double – 8 bytes
Stores dates and times in various
formats.
Stores monetary values with a fixed
number of decimal places.
A unique sequential number
automatically generated for each new
record
Stores Boolean value (True/False or
1/0)
OLE Object
Stores objects such as images, audios,
videos, word documents etc.
Hyperlink
Stores hyperlinks to web pages, files
or email addresses.
Attachment
Stores files as attachments to records.
Calculated
Lookup
Wizard
Stores the result of an expression or
formula.
Used to create a dropdown list that
stores values from another table.
Field Properties and their uses
Up to 255
characters
Up to 65,535
characters
255
-
1, 2, 4, or 8
bytes
(depending on
size)
Long
Integer
8 bytes
-
8 bytes
-
4 bytes
Long
Integer
1 byte
-
Varies
(depending on
object size)
2048
characters
Varies
(depending on
file size)
-
Varies
-
Varies
-
Field Size: It defines the maximum number of characters (for text) or the range
of numbers (for number fields) that can be stored in the field.
Example: A Short Text field with size 50 can hold up to 50 characters.
Format: It determines how the data appears in datasheets, forms, or reports.
Example: Display a date as "dd-mm-yyyy" or a number as currency.
Input Mask: It sets a pattern for entering data, helping users enter it in a
specific format.
Example: A phone number mask like (999) 000-0000 ensures correct formatting.
Caption: It sets a label that appears in place of the field name on forms and
reports.
Example: A field named DOB could have a caption "Date of Birth".
Default Value: It automatically fills the field with a preset value when a new
record is added.
Example: Default value for a “Country” field could be “Nepal”.
Validation Rule: It defines a condition that data must meet before it can be
entered into a field.
Example: Entering a number between 1 and 100: >=1 AND <=100.
Validation Text: It displays a custom error message that appears when a value
entered into a field does not meet the conditions specified in the validation rule.
Example: “Please enter a value between 1 and 100.”
Required: It controls whether data must be entered in the field or not. If set to
True, the field cannot be left blank.
Indexed: It improves search and sort performance by creating an index for the
field. Useful for fields that are frequently searched or sorted.
Uses of Form
 It provides an easy way to enter new record into a database.
 It allows users to view data in a more readable and organized format.
 It improves the user interface by including controls like buttons, text boxes,
checkboxes etc.
Report
Summarized Field Properties Table
Field Properties
Description / Uses
Field Size
Defines the maximum size for data stored in the field.
Format
Defines how data will be displayed.
Input Mask
Caption
Default Value
Validation Rule
Validation Text
Required
Indexed
Provides a template for entering data (e.g., phone
numbers or zip codes).
Sets a custom label for the field, which can be
displayed in form or reports.
Specifies a default value for the field when a new
record is created.
A report is a database object that is used to format, summarize, and present data
from tables, queries in a printable layout. It is designed specifically for printing
and presenting purpose.
Uses:
 Reports are used to present data in a clean, formatted, and printable layout.
 Reports can be used to group and summarize data.
 Reports can be designed to create custom invoices, bills, mark-sheets etc.
based on data from the database.
Filtering Records
The process of displaying only the records that meet certain criteria is known as
filtering record. It helps to focus on relevant information.
Specifies a rule that data in the field must meet.
Provides an error message when data doesn’t meet the
validation rule.
Specifies whether the field must contain data
(True = required, False = not required).
Defines whether the field is indexed for faster search
performance.
Sorting Records
Form
A form is an object of MS-Access that provides user-friendly interface for
entering, viewing, and editing data in tables. It displays data from tables or queries
in a more structured and visual manner and can also include buttons, checkboxes
and more for user input.
The arrangement of records in a table either in ascending or descending order
based on field(s) is known as sorting Record. It helps to organize data to make
easier to analyze or present. Sorting can be applied for text, date/time, number /
currency