Question

discuss the different types of information represented in ER diagram and the symbols used to represent them

Answer 1

Answer:

ER diagram:

ER digram stands for Entity-relationship diagram.ER diagram is nothing but the graphicall representation (or) illustration of an information system’s entities and the their relationships.

->It is visually represnts the entities and teir relationships.In my view ER diagram is nothing but logical structure of databases.visually means nothing but like a flowchart of a program.

->Using ER diagrams you can easily represent the entities and their relationships in visual or graphically.

-> Entity Relationship Diagram are most often used to design relational databases in software engineering, business information systems, education and research fields.

->Using Entity Relationship Diagrams you can easily Developing a conceptual design for databases.

Symbols or components of ER diagram:

In Entity-relationship diagram we are using below symbols for represent the relation ships among entities.

Entity:

Entity is nothing but things.Using Entity you can represent persons,, object, concept or event.Entity can have data stored about it.

->which are represented by rectangles

->Entities are two types strong, weak or associative.

Relationship:

Relationship is nothing but action.using Relationship you can easily represnt the how two entities share information in the database.

->Relationships are represented by diamond shape.

Attribute:

Attrribute is nothing but a property or characteristic of an entity.

->Attributes are represented using ovals.