Attributes, Entities and E-R Diagrams

Attributes, Entities and E-R Diagrams

1. Attributes

   • fact, detail or characteristic or a detail of an entity
     • Name
     • Date of birth
     • Telephone number
     • Address

2. Entities

   • a person place or thing which data can be collected by
     • customer table
     • appoinments table
     • exam sessions table

3. E-R Diagrams

   • Entity relationship diagram
     • one-to-one
       • Huband can only have one wife
     • one to many
       • mother can have many children
     • many-to-many
       • many to many are not usually found and the are not recommended to use within a databse