Week 12 Option 3: Database Design

By Robert Di Mauro and Christopher Ferrarin

What Is A Database? A database is an organised collection of

data. Data gets put in a database which turns

it into information.

Database DevelopmentPurpose Of A Database

Store large quantities of information Search and sort data quickly and

accurately to obtain the required information

Organize information Present information Update information

Database DevelopmentComponents Of A Database

FILE - A block of related data stored on a storage device.

Database DevelopmentComponents Of A Database

RECORD - A collection of data about one specific entry in a database.

FIELD - A specific piece of data in a record.

CHARACTER - The smallest unit of data that people can handle.

Database DevelopmentInputs Of A Database

Multimedia eg. Text, Hyperlinks, Videos, Sound, Pictures.

Database DevelopmentData Dictionary

A data dictionary is a comprehensive description of each field in a database and the conditions it must follow. It contains information about the characteristics of each item entered in the database, such as the field name, data type, field size and field description.

KEYS - Fields used to sort and retrieve information. A primary key is a field where each item is unique and must have a value.

One of the many items that needs to be modified to have a successful data dictionary

Database DevelopmentOutputs Of A Databse

LIST/TABLEDisplays many separate fields and records on the same screen at once.

Database DevelopmentOutputs Of A Databse

FORMDisplays all fields in a single record. Form views are also used to enter new data.

Database DevelopmentOutputs Of A Databse

REPORTReports are lists showing selected records and fields and usually show the result of a search.

Collecting, Organising and Storing Data Sources Of Data

Data needs to be structured, ordered and set up in to clear and distinct categories.

4 steps of planning data:

1. What do you want to collect?2. What is the source of the data?3. How will the data be gathered?4. How will the data be entered into the system?

Collecting, Organising and Storing Data Sources Of Data

Primary or Secondary Data?

Differences?

Homework task

Collecting, Organising and Storing Data Sources Of Data

Why is data collected? Solve problems Make sense of data

Collecting, Organising and Storing Data Database Storage On A Storage Medium

Considering File Size, Portability And Updatability

The size of a database can be extremely large.

Each record in a database is important and regular backups should be performed so that in the event of data loss it can be recovered

If the database needs to be moved how easily can that be done?

Are records easily updated?

Collecting, Organising and Storing Data Database Storage On A Storage Medium

Considering File Size, Portability And Updatability

If you had a database of Rugby League players and their game statistics when would you update the existing data?

How does this compare to the database such as EBay, who do hundreds of sales every minute?

In these 2 examples what would be an appropriate time frame to back up the data that has been entered?

Discussion is an important way to teach this part of the unit. It will allow the students to get involved and learn from each other.

Collecting, Organising and Storing Data Database Storage On A Storage Medium

Considering File Size, Portability And Updatability

There are many different ways to back up a database and they can be stored on a range of different mediums.

This relates directly to the Data Handling core topic dot point of Secondary storage such as random and sequential access and can also show the difference between offsite and onsite backups.

Collecting, Organising and Storing Data Database Storage On A Storage Medium

Considering File Size, Portability And Updatability

Records in a Database need to stay relevant and need to be updated easilyeg. Birthdate vs. Age

Inserting, deleting, moving and modifying the data structure are the major points when it comes to modifying records.

Collecting, Organising and Storing Data Validation And Verifiaction Checks

These two can be very confusing to students, the concepts are easy but some student have a very hard time distinguishing between the two

VALIDATION - Performed by the computer to minimise error when inputting data

VERIFICATION - Performed by a person once the data has been entered

Collecting, Organising and Storing Data Validation And Verifiaction Checks

These two can be very confusing to students, the concepts are easy but some student have a very hard time distinguishing between the two

VALIDATION - Performed by the computer to minimise error when inputting data

VERIFICATION - Performed by a person once the data has been entered

Methods Of Processing And Analysing DataEditing, Sorting And Searching Records Users PROCESS data by EDITING

and ANALYSE data by SORTING and SEARCHING. EDITING – The process of changing data. It

involves inserting data, deleting data, moving data and modifying the data structure.

SORTING - Sorting is the process of arranging or organising data in a particular order.

SEARCHING - Searching is the process of locating data and information. For small databases the ‘Find’ or ‘Search’ commands are sufficient.However, for large databases the most efficient way of searching is to construct a query.

Methods Of Processing And Analysing DataEditing, Sorting And Searching Records QUERY – A search of a database for records that

meet a certain condition.

Queries are constructed using an operator. Operators represent the action to be performed in the query.

Relational operators (=, <>, <, >, <=, >=) are symbols or words indicating the relationship between two expressions.

Logical operators (and, or, not) are used to combine two or more single queries.

Methods Of Processing And Analysing DataMathematical Calculations

There are a variety of mathematical calculations that can be performed in a database.

For example, you can calculate the average of the values in one field or multiply the values in two fields.

When instructing the DBMS to perform a calculation it is important to follow the correct syntax such as ‘=Avg([Salary])’.

Database calculations can be performed using either a predefined calculation, using functions such as sum, average, count, minimum and maximum, or a custom calculation, where the user writes a formula to perform a calculation such as ‘=[Salary]*1.2’ and a separate field is usually created to store the calculated results.

Methods Of Presenting InformationPresentation Of Reports

Headers appear at the beginning of the report so that meaning is given straight away.

Body text needs to go in a spot on the report that can be easily seen and easily read.

Footer appears at the bottom of the page and is set out like a tally or a total to the information presented in the report.

Methods Of Presenting InformationReport Layouts

Consistency and simplicity is the key to creating report layouts that are effective and easy to use.

Methods Of Presenting InformationDesign Features On Forms And Reports

Headings give purpose of the report.

Layouts should present the information, such as using tables or columns.

Styles should be consistent throughout .

Columns should have clear and descriptive headings.

Page numbers.

IntegrationImporting From Existing Electronic Data

Integration is the process of merging data from different sources.

Integration Integration is the process of merging data

from different sources.

IMORTING - The action of copying data produced by another program.

EXPORTING – The action to sending data to another program.

Integration Embedding occurs if the copy is not

connected to the source. The copy is fixed and does not change if the source is changed.

Linking occurs if the copy is connected to the source. If you change the data in the source it is automatically updated in the destination.

Integration Mail merge combines a document written on

a word processor or other program with data from another source such as a database.

It allows a single document to be personalised for several people.

http://www.youtube.com/watch?v=_9ExKwXQ3KQ&feature=related