Types of databases

Types of databases

1. Flat Databases

   • One Table
   • Disadvantages
     • All the information together
     • Can make mistakes easily
     • Repeating yourself a lot

2. Relational Databases

   • More than one table
   • Advantages
     • Different information in different tables. Not mixing information.
     • Mistakes are less likely to happen
     • Easier to change the information
     • Can give another person access to one table and not another
   • Features
     • Information separated into discrete entities
       • Based on real world
       • Eg Employee,product,order
     • Entities are described by a series of fields
       • Describes the structure of entities
       • Eg Product name, weight, price
     • Entities are connected by a series of relationships
       • Built using common field
       • Represented by entity relationship diagrams

3. Local Databases

   • One person uses it
     • Can be used for the finance department
     • It would be on a Personal Computer (PC)

4. Networked Databases

   • As many people has the server has can use it
   • Examples
     • Employees Information
       • Access restricted so you can't edit or delete information
       • Need to have connection to the server with a correct username and password
     • Student information
       • Need to have connection to the server with a correct username and password

5. Online Databases

   • Why they are used
     • They are used so anyone can see them anywhere. You just need an:
       • Email
       • Password
       • Internet Connection
   • Examples
     • Tesco
     • Amazon
     • Barclays