Types of databases

Types of databases

1. Flat databases

   • One table that contains all the information about the customer and what they are buying. Information is inserted manually so mistakes can be made.

2. Relational databases

   • More than one table that is all linked together, e.g. item, customer. If changes are needed then it will only need to be changed once because it will be changed throughout the whole thing. An advantage could be that each table is about one particular information so no information will be mixed.
   • Features
     • Information separated in to discrete Entities
       • Based on the real world
       • E.G employees, product, order
     • Entities are describe by a series of Fields
       • Describes the structure of the entities
       • E.g product names, weight, price etc
     • Entities are connected by a series of rlationships
       • Built using common fields
       • Represented by entity relationship diagrams (ERDs)

3. Local

   • Only one person can access a local database.

4. Network

   • Can be accessed by however many people the network can hold, but access is restricted. This is so that they will not be able to delete or change any private information by accident.

5. Online

   • Examples
     • Ebay
     • Amazon
     • Tesco
     • Barclays
   • They are used because anyone is able to use it as long as they have internet connection and an account.