4.3.1 Entities and attributes

• Entity


  Any item about which we want to store information and is the fundamental building block for relational databases
• Entities


  • Can be tangible, such as a person, a car or an album
  • Can be intangible, such as an invitation to an event
• Attribute


  Describes an entity, such as a student's name, date of birth, address, etc.
• Whilst Colin Cherry and Sara Singh are both instances of the Student entity and have the same attributes, their attributes have different values
• Course


  A collection of information possessing a name and duration in weeks, so it should be considered an intangible entity
• Since there are two entities in College_Table, we need two tables: Student_Table and Course_Table
• A record holds data about a single instance of an entity; a field stores data about one attribute of those entities
• Attributes of Student entity


  • Family_Name
  • Given_Name
  • Date_of_Birth
  • Address
  • Postcode
• Attributes of Course entity


  • Course
  • Sessions
  • Fee