Databases

Today you will: Learn what a database is and how it is used Learn how a database is organised Learn about different field types

What is a database? Any ideas? A database is any collection of information that has something in common. It does not matter whether or not this information is stored on a computer. e.g. a telephone book, a set of top trumps cards

Any of you played Pokémon? The Pokédex is a database!

Can you think of any others? An Address book. Information about a CD or Video collection. Information about pupils in a school. A Library catalogue. An encyclopaedia

Why are they used? To get information about certain “things” for certain purposes e.g. look up a telephone number for a specific person Find out what medical conditions a certain pupil has

Example: Here is a database Sort the cards into alphabetical order Now select the cards that have the names of animals that begin with the letter “D” Now select all the animals that live in “Woodland” Now select the cards with the animals that are “mammals” and begin with the letter “E” Now select all the “birds” that begin with the letter “C” that live in “Woodland” that eat “Insects”

Any ideas what we could use to make this exercise a whole lot easier? Use a Computer!!!!!

Can you think of any reasons why a computer is better than a paper based system?

It saves space You can store hundreds and in some cases thousands of pages of information onto one floppy disc. You can store all the text of the 22 volume Encyclopaedia Britannica onto one CD Rom and still have space for pictures as well!

It can save time If you type in a simple search query, you can look up information about a particular item such as a list of books written by Charles Dickens. A computer can search through many records very quickly

You can quickly produce a list of information about parts of the database that have something in common. For example a travel agent can produce a list of all the people who booked a holiday to Florida this year. He can then look further at that list to see if these people had anything else in common. For example, where do they live?

How do you go about setting a database up? The first thing you have to do is decide what information you are going to collect. You then have to decide how you are going to record this information.

What information can we collect from this application form? Surname Initials Address Postcode Tel No Subscription type Sex Date of Birth Date Membership Number

Looking at the form, we were required to input answers e.g. in the boxes next to Surname we would be required to enter an answer…. The surname part is known in a database as a “Field” The answer given is known as the “data”

Fields can contain different types of data….these are: Text whole numbers decimal numbers Dates Yes/No (Logical) answers Lookup / list

Here are the fields for the form again, what are the data types Here are the fields for the form again, what are the data types? Text, whole numbers, decimal numbers, Dates, Yes/No (logical) answers, Lookup/List? Surname Sex Initials Date of Birth Address Postcode Tel No Subscription type Date Membership Number

Here is an example of information stored in a computer database Sandwich name Price Type Date made Message Extra info Egg and Tomato £1.30 Sandwich 11/18/2004 Please consume on day of purchase Suitable for vegetarians £1.50 Roll Ham and Salad With Mayonnaise Cheese and Tomato £1.40 Cheese and Pickle Chicken Salad £1.70 Tuna with Sweet corn Salad £1.60 MAY CONTAIN NUTS Three Cheese £0.00 Where are the fields? Where are the data?

Records: all the information about something i.e. a row in the table Fields i.e. the columns Data Sandwich name Price Type Date made Message Extra info Egg and Tomato £1.30 Sandwich 11/18/2004 Please consume on day of purchase Suitable for vegetarians £1.50 Roll Ham and Salad With Mayonnaise Cheese and Tomato £1.40 Cheese and Pickle Chicken Salad £1.70 Chicken Salad £1.50 Sandwhich 11/18/2005 Please consume on day of purchase With Mayonnaise Records: all the information about something i.e. a row in the table

Task: Complete the worksheet to the best of your ability