Databases

23 November 2010

Transformation

Data Information Knowledge Action

Data vs. Information

Data – a collection of facts made up of text, numbers and dates:

Murray 35000 7/18/86

Information - the meaning given to data in the way it is interpreted:

Mr. Murray is a sales person whose annual salary is $35,000 and whose hire date is July 18, 1986.

Differences

Data› Unprocessed

Information› Organized and communicated

Knowledge› Evaluated and usable

What is a database?

storage space for information

Non-electronic Examples

A filing cabinet,

an address book,

a telephone directory,

a timetable, etc.

Electronic Database Systems: Then

Now

From Friendster.com on-line tour

Databases you may use

Benefits

Making information useful

Making information easily accessible

Integrating information

Basic Database Concepts

Name: Barry HarrisCollege: BusinessTel: 962-5555

Name: Barry HarrisCollege: BusinessTel: 962-5555

Name: Barry Harris Field

Record–A collection of data

about an individual item

–A single item of data common to all records

Table–A set of related records

Fields

Basic elements of content

An Example of a Table

Records

Fields

Name email Phone College

Graff rgraff 962-3900 Pharmacy

Harris bharris 962-5555 Business

Ipswich zipswich 933-5656 Journalism

Primary Keys & Foreign Keys

To ensure that each record is unique in each table, we can set one field to be a Primary Key field.

A Primary Key is a field that that will contain no duplicates and no blank values.

Foreign Keys link to data in other tables

Name email Phone College

Graff rgraff 962-3900 Pharmacy

Harris bharris 962-5555 Business

Ipswich zipswich 933-5656 Journalism

A Sample Relational Database

Other parts of a database

Tables

Forms

Queries

Reports

Forms A friendlier view of the database Used for data input, display and

printing

Queries

A means of asking questions (querying) of your data

Can look across tables

Reports If the query is a

question... ...then the report is

its answer Tailored to the

needs of the user Allows you to group

and summarize data

Cannot edit

Databases in Spreadsheets

Can be done› Example

BUT other tools exist to make it easier› User not need to understand as much› Handles routine operations