Download What is a Database?

Advanced Computer
Programming
Databases
1
Overview
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What is a database?
Database Basics
Database Components
Data Models
Normalization
Database Design
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What is a Database?
A database stores large amounts of information
to be retrieved or compared through a series
of queries and relationships.
Databases can retrieve information very
quickly. They can even be used to
synthesize new data from information that is
stored; a process called data mining.
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IT: Advanced Computer Programming – Databases
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Database Basics
Database Management is an important part of
working with a database. This is usually
done through a Database Management
System (DBMS). A DBMS is software that
guides the creation and maintenance of a
database.
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IT: Advanced Computer Programming – Databases
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Database Basics
Most common tasks with a database are called
transactions or queries. A transaction or
query can be placement, retrieval or
modification of data within the database.
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IT: Advanced Computer Programming – Databases
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Database Basics
Other database management tasks are:
 Creating an organized structure for the data
 Creating a simple to use interface for the data
 Setting up reporting for inquires and response
 Creating backup copies of the database
 Recovering data from a backup
 Manage security on the database
 Provide a language for searching the database
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IT: Advanced Computer Programming – Databases
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Database Components
Entity
An entity is a person, place, thing or event that
can be modeled in a data base.
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IT: Advanced Computer Programming – Databases
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Database Components
Field
A field is an attribute of an entity, such as a
name, address, cost, or quantity in stock.
Fields are defined with three properties:
 Data type such as a String, number or date
 Identifier -- a name to classify the data
 Size usually in characters -- how large the data
is
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IT: Advanced Computer Programming – Databases
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Database Components
Record
A record is a collection of related fields. For
example, a person’s name, address and
phone number might be a complete record
for a contacts database.
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IT: Advanced Computer Programming – Databases
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Database Components
Table
A table is a collection of records of the same
type -- a collection of names and addresses
as in a contacts list, for example.
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IT: Advanced Computer Programming – Databases
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Database Components
Key
A key is a field or attribute used to identify
information in a database. Keys are typically
used to store and retrieve information in the
database.
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IT: Advanced Computer Programming – Databases
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Database Components
Primary Key
The key to an entity that is usually the most
important piece of information about the
entity. The primary key needs to be as
unique as possible. Names, for example, are
very poor keys while ID numbers, account
numbers or work order numbers are better.
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IT: Advanced Computer Programming – Databases
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Data Models
There are several types of Data Models that
can be used to store information in a
database:
 Flat file
 Relational
 Object Oriented
 Multimedia
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IT: Advanced Computer Programming – Databases
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Data Models
A Flat File database is a basic database
model that simply stores information without
taking into account any other concerns.
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IT: Advanced Computer Programming – Databases
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Data Models
A Relational database stores relationships
between different data items and can be used
to retrieve and store information based on
those relationships.
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IT: Advanced Computer Programming – Databases
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Data Models
Object Oriented databases (OO) are based
on object models used in computer
programs. An OO database is typically used
to store complete software objects.
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IT: Advanced Computer Programming – Databases
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Data Models
A Multimedia database is specifically
designed to hold videos and music files as
well as other types of multimedia.
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IT: Advanced Computer Programming – Databases
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Data Models
In addition, there are functional models:
Operational databases are designed to allow
interactive transactions such as inventory
control.
Data Warehouse databases store static
information intended for lookup and data
mining.
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IT: Advanced Computer Programming – Databases
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Normalization
Normalization is a process which removes
redundancy from a database and helps
remove inconsistencies.
Normalization is done in a series of forms
where information is grouped into evernarrowing categories.
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IT: Advanced Computer Programming – Databases
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Database Design
Steps to Database Design:
1. Requirements analysis
2. Create fields necessary to store data
3. Create tables and normalize them
4. Define data Relationships
5. Evaluate performance and determine if the
database meets the client’s needs
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IT: Advanced Computer Programming – Databases
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