E R Diagramm. Er diagrams are used to sketch out the design of a database. It shows all the constraints and relationships that exist among the different components.
Components of er diagram an er diagram is mainly composed of following three components. Er diagrams are created based on three basic concepts. You can use so popular chen s notation to represent all components of database and their relationships on the er diagram.
The main components of the e r diagrams are.
Er diagram er diagram or entity relationship diagram is a conceptual model that gives the graphical representation of the logical structure of the database. At first look an er diagram looks very similar to the flowchart. Er diagrams are created based on three basic concepts. By defining the entities their attributes and showing the relationships between them an er diagram illustrates the logical structure of databases.
