Ado.net Entity Framwork

• It is a object-relational mapping(ORM) framework for .Net Framwork
• It genarate one to one mapping between the database schema(physical schema) and the conceptual schema(logical schema)
• The Mapping betweeen logical schema and physical schema represent by ENTITY DATA MODEL(EDM)
• EDM specifies conceptual model of data by ENTITY-RELATIONSHIP DATA MODEL(ERDM)
• ERDM deals with Entities & Relationship
• Entity are instance of Entity Type (eg.Customer table,employee table). it consist of rich set of records with a key.Entity are grouped in Entity Set
• Relationship are associates Entities,and are instance relationship type.Relation are Relation ship set
• Other concept related to EDM are inheritance , complex types
• Inhertiance:Entity types can defined so they inherit form other type.Inhertance is a strictly strucutal meaning not as behaviour inheritance as object oriented programing
• Complex type:EDM support addtional to scalar data type .it support complex type
• Basic Concept of EDM
1. Entity Types:An Entity type defines princpal Data objects about which information has to managed such as a person ,Place,Thing,Activities relevant to the application
2. Property:Entity Type can have one or more properties
3. Property types
• Simple Type:It Corresponds to simple Data type(int,char,floating point)
• Complex Type:It is an aggregate of multiple properties of type simple type,complex type,row type
• Row Type:It is similar to complex type,except they can not inherted

• Entity Key:All instantce of entitytype are unique identified by the value of its identity properties.This set entity properties is called an ENTITY KEY
• RelationShip Type:while Entities types are noun pf a data model,Relationship type are verb that conects those nouns.
• RelationshipType support by EDM 1)Association 2)Contianment
1. Association:it is peer to peer relation ship
2. Containment:It is parent child relationship with spefice member semantices

• Schema:All EDM types contained with some namespace.The schema concepts defines a namspace that describes the scopes of EDM types
• Entity Container:EntitysET & Relationship set are defined in the scope of Entity Container.it can reger one or more schema

• Ado.net Entity framework uses as an xml based defination language called schema defination language(SDL)

Refered Links: MSDN en.wikipedia.org