Business Rules and Data Abstraction

• A business rule is a set of approved guidelines or framework within an organization.
• A business rule is a statement that imposes some form of constraint on a specific aspect of the database.
• Types of Business Rules

  Database - oriented: Database oriented business rules impose constraints that you can establish within the logical design of the database. You implement a given constraint by modifying various field specification elements, relationship characteristics, or a combination of the two.
• Types of Business Rules

  Application-oriented: Application oriented business rules impose constraints that you cannot establish within the logical design of the database. You must instead establish them within the physical design of the database or within the design of a database application, where they will be more applicable and meaningful.
• Data Abstraction refers to the process of hiding irrelevant details from the user.
• Data Independence - users and data should not directly interact with each other. The user should be at a different level and the data should be present at some other level.
• View Level - This level tells the application about how the data should be shown to the user.
• Conceptual Level - This level tells how the data is actually stored and structured.
• Physical Level - tells us that where the data is actually stored; it tells the actual location of the data that is being stored by the user.