Database.pptx

IN THE NAME
OF
ALLAH THE
ALMIGHTY

Database Fundamentals
Data : Data, in the context of databases,
refers to all the single items that are
stored in a database, either individually
or as a set. Data in a database is
primarily stored in database tables such
as people, objects, or events

Information : Data that have been
processed and presented in a form
suitable for human interpretation

Database
A database is a shared collection of
logically related data that is stored to
meet the requirements of different users
of an organization

File System vs Database
Basis File System DBMS
Structure
The file system is a way of arranging the files
in a storage medium within a computer.
DBMS is software for managing the database.
Data Redundancy
Redundant data can be present in a file
system.
In DBMS there is no redundant data.
Backup and
Recovery
It doesn’t provide backup and recovery of data
if it is lost.
It provides backup and recovery of data even
if it is lost.
Query processing
There is no efficient query processing in the
file system.
Efficient query processing is there in DBMS.
Consistency
There is less data consistency in the file
system.
There is more data consistency because of the
process of normalization.

File System vs Database
Complexity It is less complex as compared to DBMS.
It has more complexity in handling as
compared to the file system.
Security Constraints
File systems provide less security in
comparison to DBMS.
DBMS has more security mechanisms as
compared to file systems.
User Access Only one user can access data at a time. Multiple users can access data at a time.
Sharing
Data is distributed in many files. So, not easy
to share data
Due to centralized nature sharing is easy
Data Abstraction
It give details of storage and representation of
data
It hides the internal details of Database
Integrity
Constraints
Integrity Constraints are difficult to implement Integrity constraints are easy to implement

Database Management system (DBMS) : A
database management system (DBMS) is
system software for creating and managing
databases. A DBMS makes it possible for
end users to create, protect, read, update and
delete data in a database.
Examples : MySQL · Microsoft Access · Oracle

Types of Database
Hierarchical Databases : Just as in any
hierarchy, this database follows the
progression of data being categorized in
ranks or levels

Types of Database
Relational Database : In a relational database
management system (RDBMS), the
relationship between data is relational and
stored in tabular form of columns and rows.
Each table column represents an attribute,
and each Row in a table represents a record.
Each field in a table represents a data value.

Components of a relational database
Table/Relation : Everything in a
relational database is stored in the form
of relations.
The RDBMS database uses tables to store data.

Table/Relation
A table is a collection of related data
entries and contains rows and columns to
store data. Each table represents some
real-world objects such as person, place,
or event about which information is
collected.

Table/Relation
Properties of a Relation:
Each relation has a unique name by
which it is identified in the database.
Relation does not contain duplicate
tuples.

Table/Relation
The tuples of a relation have no
specific order.
All attributes in a relation are atomic,
i.e., each cell of a relation contains
exactly one value.

Table/Relation
ID Name AGE COURSE
1 Ali 24 B.Tech
2 Aryan 20 C.A
3 Manahil 21 BCA
4 Rani 22 MCA
5 Adnan 26 BSC

Table/Relation
Row or record
A row of a table is also called a record or
tuple. It contains the specific information
of each entry in the table. It is a
horizontal entity in the table. For
example, The above table contains 5
records.

Table/Relation
Properties of a row
 No two tuples are identical to each other in all their
entries.
 All tuples of the relation have the same format and
the same number of entries.
 The order of the tuple is irrelevant. They are
identified by their content, not by their position.

Table/Relation
Column/Attribute : A column is a vertical
entity in the table which contains all
information associated with a specific
field in a table. For example, "name" is a
column in the above table which contains
all information about a student's name.

Table/Relation
Properties of an Attribute
 Every attribute of a relation must
have a name.
 Null values are permitted for the
attributes.

Table/Relation
 Default values can be specified for an
attribute automatically inserted if no
other value is specified for an
attribute.
 Attributes that uniquely identify each
tuple of a relation are the primary key.

Table/Relation
Name
Ajeet
Aryan
Mahesh
Ratan
Vimal

Form
In a database context, a form is a window
or screen that contains numerous fields, or
spaces to enter data. Each field holds a
field label so that any user who views the
form gets an idea of its contents
Components of a database

Query
A database query is a request for data from
a database. The request should come in a
database table or a combination of tables
using a code known as the query language.
This way, the system can understand and
process the query accordingly.

 Below are some of the most common query
commands along with their functions
SELECT – fetch data from the database. It’s one
of the most popular commands, as every request
begins with a select query.
AND – combine data from one or more tables.
CREATE TABLE – build different tables and
specify the name of each column within.
Query

ORDER BY – sort data results either numerically
or alphabetically.
UPDATE – modify existing rows in a table.
INSERT – add new data or rows to an existing
table.
WHERE – filter data and get its value based on a
set condition.
Query

REPORT
A database report is a document that summarizes
the data stored in a database. It is an excellent
way to organize, analyze, and present data in an
easy-to-understand format. Reports are used in
many industries, including business, healthcare,
government, and education, to communicate
important information to stakeholders.

Database Keys
Keys : Keys play an important role in the
relational database.
It is used to uniquely identify any
record or row of data from the table. It
is also used to establish and identify
relationships between tables.

Database Keys
Types of keys:

Database Keys
Primary key : It is the first key used to
identify one and only one instance of an
entity uniquely.

Database Keys
Foreign key : Foreign keys are the
column of the table used to point to the
primary key of another table.

Database Relationship
The backbone of any relational database
is a database relationship. Once you have
defined tables, you can relate the data
held in different tables.

One-to-One
A record in Table-A relates to one
matching record in Table-B, and each
record in Table-B relates to one
matching record in Table-A.

Each record in the Employee table is
about one employee. That record relates
to only one record in the Pay table. Each
record in the Pay table relates only one
record in the Employee table.

One-to-Many
A record in Table-A can have many
matching records in Table-B, but a
record in Table-B can have only one
matching record in Table-A.

A one-to-many relationship is the most
common relationship found between tables
in a relational database. The Customer table
holds a unique record for each customer.
Each customer can place many orders.
Many records in the Order table can relate
to only one record in the Customers table.

Many-to-Many
In a many-to-many relationship, each
record in both tables can relate to
many records in the other table. These
relationships require a third table,
called an intermediary table.

The relationship between the Customer
and Order table is one-to-many. But the
relationship between the Order table and
Product table is many-to-many.

An order can contain multiple products, and a
product could be linked to multiple orders as
several customers might submit an order that
contains the same products. This kind of
relationship requires a minimum of three
tables.

Database.pptx

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