Data Types
When designing a database, consideration needs to be given to the data type of the field.
- Text
- Number
- Date
- Time
- Graphics
- Calculation
- Link
- Boolean
- Key Field
Text
Used to store letters of the alphabet or a mixture of letters and numbers such as postcode
Examples:
Name: Gavin McLeod
Registration: SN62 FHV
Mobile: 07545661120
Number
Integer – used to store whole numbers with no decimal point
Real – used to store numbers which could be decimals
Examples:
Year Established: 2005
Days Absence: 4
Weight: 12.5
Date
Used to store a day, month or year using a variety of formats
Examples:
Date of Birth: 31/05/2003
Date of Employment: 3 July 2020
Time
Used to store hours, minutes and seconds
Examples:
Appointment: 16:50
Period End: 12:45
Graphics
Used to store a different type of data file such as graphics, sound or video
Examples:
Club Crest:
Photograph:
Calculation
Calculations can be performed on fields using a formula
Examples:
Total Pupils
A database stores the details of each tutor class in a school. One of the fields is a numeric field called Pupils, which stores the number of pupils in the class. Total Pupils is a calculated field, adding the Pupils field from each record
Average Bill
A database stores the details of a shopping bills in a supermarket. One of the fields is a numeric field called Total Bill which stores the amount of each bill. Average Bill is a calculated field to determine the average of each bill.
Link
A web link
Examples:
Official Band Home Page: www.foofighters.com
Contact Page: www.vodafone.co.uk/contact-us
Boolean
A Boolean can store one of two values, True or False (or Yes/No)
Examples:
Club Member: True
Driving Licence: False
Key Field
Unique field that stores the key for each record
Examples:
Student ID: 07151102
Product ID: B-1201-FG7315
