Transcript Data Manipulation Component

BUSINESS DRIVEN
TECHNOLOGY
Chapter Seven:
Storing Organizational
Information - Databases
LEARNING OUTCOMES
7.1 Define the fundamental concepts of the relational
database model
7.2 Evaluate the advantages of the relational
database model
7.3 Compare operational integrity constraints and
business-critical integrity constraints
LEARNING OUTCOMES
7.4 Describe the role and purpose of a database
management system
7.5 List and describe the four components of a
database management system
7.6 Describe the two primary methods for integrating
information across multiple databases
CHAPTER SEVEN OVERVIEW
• Information is everywhere in an organization
• Information is stored in databases
– Database – maintains information about various types
of objects (inventory), events (transactions), people
(employees), and places (warehouses)
CHAPTER SEVEN OVERVIEW
Start
RELATIONAL DATABASE
FUNDAMENTALS
• There are numerous database models including:
– Hierarchical database – stores related information in
terms of predefined categorical relationships in a “treelike” fashion
– Network database – used by a network installation tool
to allocate and track network resources
– Relational database model – stores information in the
form of logically related two-dimensional tables
Entities, Entity Classes, and Attributes
• Entity – a person, place, thing, transaction, or
event about which information is stored
– The rows in each table contain the entities
– Figure 2.6 on page 63, CUSTOMER includes Dave’s
Sub Shop and Pizza Palace entities
• Entity class (table) – a collection of similar entities
– Figure 2.6 on page 63 includes CUSTOMER, ORDER,
ORDER LINE, DISTRIBUTOR, and PRODUCT entity
classes
Entities, Entity Classes, and Attributes
• Attributes (fields, columns) – characteristics or
properties of an entity class
– The columns in each table contain the attributes
– Figure 2.6 on page 63, attributes for CUSTOMER
include Customer ID, Customer Name, Contact Name,
and Phone
Keys and Relationships
• Primary keys and foreign keys identify the various
entity classes (tables) in the database
– Primary key – a field (or group of fields) that uniquely
identifies a given entity in a table
– Foreign key – a primary key of one table that appears
an attribute in another table and acts to provide a
logical relationship among the two tables
Keys and Relationships
Start
Keys and Relationships
• Potential relational database for Coca-Cola
RELATIONAL DATABASE ADVANTAGES
• Database advantages from a business perspective
include
– Increased flexibility
– Increased scalability and performance
– Reduced information redundancy
– Increased information integrity (quality)
– Increased information security
Increased Flexibility
• A well-designed database should:
– Handle changes quickly and easily
– Provide users with different views
– A database has only one physical view
• Physical view – deals with the physical storage of
information on a storage device such as a hard disk
– A database can have multiple logical views
• Logical view – focuses on how users logically access
information to meet particular business needs
Increased Scalability and Performance
• A database must scale to meet increased demand,
while maintaining acceptable performance levels
– Scalability – refers to how well a system can adapt to
increased demands
– Performance – measures how quickly a system
performs a certain process or transaction
Reduced Information Redundancy
• Databases reduce information redundancy
– Redundancy – the duplication of information or storing
the same information in multiple places
• Inconsistency is one of the primary problems with
redundant information
Increase Information Integrity (Quality)
• Information integrity – a measure of the quality of
information
• Integrity constraints – rules that help ensure the
quality of information
– Operational integrity constraints – rules that enforce
basic and fundamental information-based constraints
– Business-critical integrity constraints – rules that
enforce business rules vital to an organization’s
success and often require more insight and knowledge
than operational integrity constraints
Increased Information Security
• Information is an organizational asset and must be
protected
• Databases offer several security features including:
– Passwords – provide authentication of the user
– Access levels – determine who has access to the
different types of information
– Access controls – Determine types of user access,
such as read-only access
DATABASE MANAGEMENT SYSTEMS
• Database management systems (DBMS) –
software through which users and application
programs interact with a database
DATABASE MANAGEMENT SYSTEMS
• Four components of a DBMS
Data Definition Component
• Data definition component – helps create and
maintain the data dictionary and the structure of the
database
• The data definition component includes the data
dictionary
– Data dictionary – a file that stores definitions of
information types, identifies the primary and foreign
keys, and maintains the relationships among the tables
Data Definition Component
• The data dictionary essentially defines the logical
properties of the information that the database
contains
Data Manipulation Component
• Data manipulation component – allows users to create,
read, update, and delete information in a database
• A DBMS contains several data manipulation tools:
– Views – Allows users to see, change, sort, and query the
database content
– Report generators – users can define report formats
– Query-by-example (QBE) – users can graphically design the
answers to specific questions
– Structured query language (SQL) – query language
Data Manipulation Component
• Sample report using Microsoft Access Report
Generator
Data Manipulation Component
• Sample report using Microsoft Access Query-ByExample (QBE) tool
Data Manipulation Component
• Results from the query in Figure 2.11
Data Manipulation Component
• SQL version of the QBE Query in Figure 2.11
Application Generation and Data
Administration Components
• Application generation component – includes
tools for creating visually appealing and easy-touse applications
• Data administration component – provides tools
for managing the overall database environment by
providing faculties for backup, recovery, security,
and performance
• IT specialists primarily use these components
INTEGRATING INFORMATION AMONG
MULTIPLE DATABASES
• Organizations typically maintain multiple systems,
each with its own database
• Integration – allows separate systems to
communicate directly with each other
INTEGRATING INFORMATION AMONG
MULTIPLE DATABASES
• Forward integration – takes information entered
into a given system and sends it automatically to all
downstream systems and processes
INTEGRATING INFORMATION AMONG
MULTIPLE DATABASES
• Backward integration – takes information entered
into a given system and sends it automatically to all
upstream systems and processes
INTEGRATING INFORMATION AMONG
MULTIPLE DATABASES
• Building a central repository specifically for
integrated information
OPENING CASE STUDY QUESTIONS
Searching for Revenue - Google
1. Identify the different types of entity classes that
might be stored in Google’s indexing database
2. Explain why database technology is so important
to Google’s business model
3. Explain the difference between logical and
physical views and why logical views are
important to Google’s employees
CHAPTER SEVEN CASE
Hotcourses Increases Revenues by 60 Percent
•
Hotcourses is one of the hottest new ebusinesses in London
•
Offers a comprehensive online educational
marketplace
•
After two years of operation the company
estimates revenues for 2003 between $100 and
$500 million
CHAPTER SEVEN CASE QUESTIONS
1.
Identify the different types of entity classes and attributes
potentially maintained in the Hotcourses database
2.
Describe the two different ways that employees at
Hotcourses might access the information in their
databases
3.
Create two questions that a manager at Hotcourses
could turn into queries and run against a database to
discover business intelligence