Entity relationship model

The ppt will give the information about the ER-model.
and also here I added one ER-diagram of Placement Management System which will help anyone to understand the components of ER-diagram.

1. DBMS ISE 1 E-R MODEL Presented by- PRN No.: 1910049 Class: T.Y. B. Tech.

2. ER Diagram stands for Entity Relationship Diagram, also known as ERD is a diagram that displays the relationship of entity sets stored in a database. In other words, ER diagrams help to explain the logical structure of databases. What is ER diagram?

3. Need of E-R Diagram An entity-relationship diagram, or ER diagram, is essential for modeling the data stored in a database. It is the basic design upon which a database is built. ER diagrams specify what data we will store: the entities and their attributes. They also show how entities relate to other entities. Another advantage of E-R diagram is that they represent the data in a graphical manner.

4. R e c t a n g l e r e p r e s e n t s t h e entity sets. E lli p s e r e p r e s e n t s t h e attributes. D i a m on d r e p r e s e n t s t h e relationship sets. Lines link attributes to entity sets and entity sets to relationship sets. Double ellipse represents multivalued attributes. Dashed ellipse represents the derived attributes. Primary key attributes are underlined. Components of ER diagram

5. Thus, we have studied what is E-R Diagram, what are the components of the E-R diagram. We have also seen how attributes and entity sets are related to each other. C o n c l u s i o n

6. Thank you! Do you have any questions for us?