There are two types of visual techniques in data modelling, they are:

• Entity-Relationship (ER) Model: This is a data modelling methodology that DESIGNS traditional databases and aids in performing data normalization by reducing data redundancy. It helps in database schema visualization of top-level data view. The data modelling architect identifies the FOLLOWING:
  • Entities and their attributes that represent objects/tables in the relational databases.
  • Relationships between the entities.
• UML (Unified Modelling Language): UML is a general-purpose language used in database modelling, development and visualization in software ENGINEERING. It consists of different diagrams for representing the software SYSTEMS and one of them is Class Diagram. Class diagrams are close similar to ER diagrams and define the following:
  • Classes - equivalent to an entity in the relational world.
  • Class Attributes that represent the properties.
  • Class Methods that REPRESENTS the behaviour of a class.
  • Relationships - between class instances (Association/Composition/Aggregation) or between classes (Inheritance/Realization/Generalization).