Identifying Photographs

Starter“All photographs are stored on the main server of the computer system at the Head Office. Each photograph is given a reference made up of the first four letters of the surname of the person who booked the session and four digits based on the order in which the photograph was taken during the session. Image Reflections would like to improve this system and is considering using a database to store details of individual photographs.”• Write down three sample photo reference codes based on

the information from the scenario above

Photo Reference Codes

• When a customer selects a photo to get final prints, they may need to put the code on the purchase form

• They need to be unique and easy to write accurately

Problems with the Current System

• What do you think they might be?– Limit to number of photos taken – 9999

• This isn’t a big problem – that’s a large number!

– Booking a second session• How can we tell which one is which?

– People with the same surname• E.g. how many Smiths are there in this school? In all of

Birmingham?

• What happens if two book sessions at different times?– Do photos get ‘overwritten’?

– Do they use a different code for them – if so how easy is it to know whose is whose?

Keyword: Database

• A Database is a program for storing data in a structured way that makes it easy to sort and search to find information

• In year 9 you created a database to store data for the company using Microsoft Access

Flat File Database

• Looks no different to a table in Excel – a grid of columns and rows

Field Name

A RecordThe actual photo data could be stored in the database or just a link to the file

Database Keywords:• A Record is all the data stored about one

individual thing – a photo in this table• A field name describes what one individual

piece of data is, e.g. ‘description’• Updating or editing means changing a

record• Deleting means removing a record• Creating means making a new record• A Query is a search in a database for specific

information using a condition

Problems with a flat file database

• We’ve expanded the database a little

• Look for repeated data below

• What would happen if Anne Smith moved house?

Keyword: Data Redundancy

• Data redundancy means that there is data in the database that is pointlessly repeated – it’s a problem because if something needs to be changed then it all has to be changed and it’s easy to make a mistake and miss some

Relational Database

• In a relational database we have more than one table but they’re connected up

This table is called “Booker”

This table is called “Photo”

Relational Database

• In a relational database we have more than one table but they’re connected up

Relational Database

• In a relational database we have more than one table but they’re connected up

Primary Key – unique in that table

Foreign Key – makes a link to a PK in another

table

Relational Database

• Redundancy is reduced or removed by having each person’s data stored only once in one table so there’s only one place to edit if they need to make changes

Task:

• Re-read the presentation and update your notes to make sure you have everything spot on

• Use this information to help answer the questions on your sheet (which will go in your folder/book)

Plenary

In a sentence, summarise your learning –be ready to share with the class!

• In this lesson I have learned…