Database

1
Database

• Definition
• Structure
• Parts
• Types

2
Database

• database - organized collection of data that may
  reside in multiple files
• database software - stores, organizes and
  retrieves the data

3
The Electronic File Cabinet Database Basics

• Like word processors, spreadsheets, and graphics
  programs, database programs are applications.
• Database programs are designed to maintain
  collections of information stored on computer
  disks.

8.04
4
The Electronic File Cabinet Database Basics

• What Good Is a Database?
• Whats a Good Database System?
• Database Anatomy
• Database Operations

8.04
5
What Good Is a Database?

• Databases make it easier to
• store large quantities of information.
• retrieve information quickly and flexibly.
• organize and reorganize information.
• print and distribute information in a variety of
  ways.

8.05
6
Whats a Good Database System?(Properties)

• data integrity- the validity of the data
• data independence - the way an application
  program displays the data does not have to be the
  same way the data is physically stored

7
Whats a Good Database System?(Properties)

• data redundancy - repetition of data
• data security - access to data (sensitive) or
  protection against loss
• data maintenance - ease of adding, deleting and
  updating records

8
Database Anatomy An Electronic File Cabinet
made up of files, which are
Databases are
made up of records, which are
made up of fields.
8.06
9
Database Terms
Field
Record
File
Key Field
Objects
Relationship
10
Database Terms
Examples First name middle initial phone
no. catalog no.
One unit or piece of data the more precise each
field is, the more efficient the
database management is when you start
searching and manipulating data
Field
11
Database Terms
Examples a drivers license, all the
info about each catalog item
A collection of all related fields about one
person, place or thing
Record
12
Database Terms
Examples All drivers licenses for
a state, all items in a catalog
A collection of records related to the same topic
File
13
Database Terms
Examples SS number catalog item
filename customer numeric count
A field containing different (unique) information
for each record in a database if you dont
identify a key field, Access can assign one.
Key Field
14
Database Terms
Examples Tables forms reports queries macros mo
dules
Items attached to a database to hold data stored
in the database
Objects
15
Database Terms
Examples Using Social Security , item
number, or Vendor no. to tie data from one
table to data from another table
An association established between tables using
fields that the tables have in common
Relationship
16
View

• View a display of the information in fields
  based on a particular arrangement of field data.
• Two views list (in Access this is called
  Datasheet view) and browse (form view)
• list - a table, see records line by line
• browse - see one record at a time in the guise of
  an onscreen form

8.07
17
Database Operations

• Database commands are used to retrieve, organize,
  print and distribute database information.
• Import
• Browse
• Sort
• Report
• Query(Filter)

18
Importreceive data in the form of text files
19
Browsenavigate through information by just
looking at it.
20
Sort rearrange records (alphabetically or
numerically).
21
Report printout of an ordered list of records.
22
Queries/Filterssearch or select one or more
specific records
A set of criteria applied to records in order to
show a subset of the records or sort the records
23
The Users View
Database programs can produce a variety of
reports (or printouts). Customized reports
display an ordered list of selected records and
fields
8.09
24
Database Objects
Table
Query
Form
Report
Macros
Module
25
Database Objects
The primary unit of a database that stores field
names, field descriptions, field controls, and
field data. Tables display multiple records in
column/row format similar to a spreadsheet
layout.
Table
26
Database Objects
A structured guideline used to search database
tables and retrieve records that meet specific
conditions.
Query
27
Database Objects
An aesthetically pleasing layout of table data
designed to display one record on-screen at a
time.
Form
28
Database Objects
An organized format of database data design to
generate printouts that provide meaningful
information
Report
29
Database Objects
A mini program that stores a set of instructions
designed to perform a particular task.
Macros
30
Database Objects
A collection of Visual Basic programming
procedures stored together to customize the
Access environment.
Module
31
Database Objects

• When you create a new database, you have to name
  the database and identify the folder to store.
• Eventually you will create objects within the
  database, and Access will store the objects
  together in the same database file.

32
Special-Purpose Database Programs
databases electronic phone directories
Ready-to-use, encyclopedias, atlases, and
similar reference materials.

• Geographical information systems (GISs) include
  geographic and demographic data in map form,

8.10
33
Special-Purpose Database Programs

• Personal information managers (PIMs) an
  electronic organizer that is customized to fit
  individual needs.

8.10
34
Rules of Thumb Dealing with Databases

• Choose the right tool for the job.
• Plan ahead.
• Start small and test your database design.
• Make data consistent.
• Make use of automatic data checking.
• Query with care.
• Develop smart search methods.

8.12
35
Structure of the data

• lowest level - characters
• characters are combined to form a field (single
  item of information)
• collection of fields is a record
• records are stored in file(s)
• it is up to the database designer how the data is
  to be organized, it is up to the database
  software to retrieve, and store the information

36
Types of Database Software

• file management programs
• database management systems

37
File Management Programs

• a computer program that allows the user to store
  and manage information on a single file
• used by individuals and small businesses
• easy to learn, low price, less complex
• example - Works database

38
Database Management Systems

• A program that stores data in files structured
  into fields and records. Can use data stored in
  one file to match with several other files
• more expensive, more complex
• four different structures

39
Database Structures to Link Files

• Hierarchical
• Network
• Relational
• Object-Oriented

40
Hierarchical Databases

• links data with a hierarchical relationship
• group fields together to form a special
  relationship- looks like a pyramid
• limits the way you can search for information
  based on the relationships

41
Hierarchical Design
42
Network Databases

• also based on relationships , but a child can
  have more that one parent or none

43
Network Design
44
Relational Databases

• Most popular - Access
• Information related through a common field called
  a key
• key field - is a field that occurs in two or more
  files and serves as a bridge between them

45
Relational Database
46
Object-Oriented Databases

• based on the relationships of the objects within
  the database
• newest type - heavily used in multimedia objects

47
Parts of the DBMS Software

• Data Definition Language- used to describe the
  structure (schema)
• Schema outlines the data - each field must be
  identified with a name, length and type
• Data Manipulation Language - use to view, add,
  delete, sort and modify records

48
Parts Continued

• Query Language-asks questions of the dB
• Report Generator - design and generate reports
  based on the information within the dB

49
Questions