Shridatt Kelkar

• Feb 15th, 2007

 

A data model is a model which shows how data is stored and used for eg a normal databaseIt has 3 main parts1)Structural part:- how data is structured2)Intergrity part:- Rules governing structure3)Manipulation part:- operators used to select,update,querry that data,eg select,update,delete commands in sqlTo furhter add Data Modelling is when we add this theory to Live instance.ENTERPRISE DATA MODEL(ENTERPRISE RELATIONSHIP MODELING) :- This can be called as an conceptual model or semantic modelThe sub parts of an ERM are1)Entity:- It is an object,eg employees,computer2) Relationship:- It captures how two or more entities are related to each other3)Attributes:- Every entity has its own sets of atributes (eg PAN no in India for each employee or SSN in US)To clarify the point look at egA employye is an entity belonging to entity sets(All employees) which has a relationship with department,and attributes is emp code

rachel123

 Profile Answers by rachel123 

• Jul 16th, 2009

 

Data Model defines the data elements  and the relationship between the data elements.

The ER diagram is a kind of Data model which belongs to the Conceptual model category where in you define  the entitiy classes and the relationship between the entities 

Belirina

 Profile Answers by Belirina 

• Jan 11th, 2010

 

Actually these two terms concern to organization of a database.
Entity Relation Model is rather an approach to data modeling.
Data model is a graphic representation of relationships between entities in a database that actualizes with using Entity Relation Diagram as a tool.