Database Terminology

Database Terminology

1. Database: is a collection of data or information which is held together in an organised or logical way. (Paper based or computerised)

   • Paper Based
     • i.e notebook with addresses sorted by surname or the Yellow Pages directory which is organised by businesses.
   • Computerised
     • i.e. search engines (Google), school electronic registers

2. Why use a database?

   • Vast amounts of information can be stored
     • Banks: millions of customers, who might have more than one account (current, savings, mortgage). Many transactions will take place so the bank will need to store details of every single transaction that takes place, what time, how much, who was paid etc.
   • Queries can be run to search for specific records or groups of records
     • Bank: A customer may complain about a withdrawal of money that they do not recognise. Bank will need to search its database very quickly and find the customers account, transaction and details - can be done in seconds.
   • Reports can be produced from the data stored or queries run
     • Data can be sorted into a logical order or extracted as part of a query, but the output doesn't look very professional. If you are showing the information to a customer, producing a database report may be required.
   • Information can be extracted from the database and exported into a word processing package for mail merging
     • Spam can be sent be running queries on a database and then finding a set of records which match a set criteria.
   • Validation can be used to reduce errors
     • Validation can't stop errors, but can reduce them. Databases enable you to use a variety of validation techniques to ensure that data is 'reasonable, allowable, sensible and within acceptable boundaries'.

3. Tables

   • Allows you to see all of the records stored in the database
   • Can store many records
   • A database can contain many tables

4. Record

   • Is all of the data or information about one person or one thing
     • Each table can contain anything from a few up to millions or records/rows
     • Is made up of lots of individual pieces of information
     • Each piece of info in a record is called a field

5. Flat file database

   • All data stored in one large table