5 5 Data types Logical/Boolean Has only two alternatives: Yes or no, on or off true or false Text/Alphanumeric Refers to all letters and numbers and other characters you can see on the keyboard Numeric (Real/integer) Real has a decimal at least and integer are whole numbers, both positive and negative Date A date and formats can vary Currency

Putting data into structure Databases, spreadsheets and many other types of software require that the data is put into a structure An organized store of data is called a database Flat file databases are of limited use and only used for simple databases. Only one table with information. Relational databases don’t store all the data in one table. It stores in several tables with links between. Flat file Relational A record One row A field Vertical column Redundancy Key field

Create a database Excel and Access are two common program to create simple databases. Even though these program also have advanced functionality. Pupils Pupil number Surname Tutor group Tutor groups Tutor group Tutor number Tutors Tutor number Tutor title Tutor surname Tutor initial

Extra Foreign keys is a key that actually is a key in another one (table) as well. Analogue digital conversion