Types of relationships

Types of relationships

1. One to one

   • Examples
     • Hospitals, the patients information will be linked to their record
   • Advantages
     • linked only to one person
   • Disadvantages
     • Consumes time may result in human errors

2. One to many

   • Example
     • An ordering database can like to many customers
   • In a database it can link to many tables

3. Many to many

4. Information is stored in sets of related tables based on the entities

5. Relationship built through common fields

6. Overcome the problems of storing things in single tables

7. An entity relationship diagram (ERD) is specialised graphic that shows the relationships between entities in a database