Database

Database

1. An organized collection of related data. It is possible to add, edit, manage and retrieve data from a adatabase. The structure of a database allows data to be found and used quickly

2. Number (integer)=whole number

3. Number (real) = any number, whole, fraction and decimals

4. Text or string = letters, numbers, or other characters e.g punctuation

5. Data/time = any time or date

6. Currency = Money and currency

7. Boolean = two opposing states e.g true or false

8. Lists = list of values

9. picture = image

10. sound = a beep from a barcode

11. video = introduction video

12. field is a single item of data within a record

13. A record consists of a collection of related fields

14. a file is a collection of related fields

15. key field uniquely identifies each record

16. validation methods can only ensure reasonable and sensible data

17. Range check: data entered is a sensible range

18. type check: data is correct type

19. format/ picture check: if it has a particular pattern

20. Calculated fields: not all data needed in a report may be present in a database.

21. Uses of database

    • Add, change or delete records
    • Search for a particular record
    • Sort the records into a given order
    • Print reports about some aspect of the database

22. A report is a printed document that contains data from the database, organised and analysed in a certain way.

23. Why sort data?

    • Easier if lists are printed as a report
    • You can identify best customer by amount they spend