NET Entity Framework overcomes all of these issues and affords
some additional features. To solve the problem of connecting OO systems to relational data, the Entity
Framework maps relation objects (tables, columns, and primary and foreign keys) to entities and
relationships in conceptual models.
The conceptual model comes from the division of the data model into three distinct parts:
??‘ Conceptual??”Defines the entities and relationships from the system being modeled.
??‘ Logical??”Normalizes the entities and relationships into ??????relational??™??™ tables and constraints.
??‘ Physical??”Handles the physical storage engine needs and capabilities of the particular data storage
engine.
A developer need not be concerned about the physical aspects of the model. That is primarily the
responsibility of a DBA. Today, developers typically focus their attention on the logical model by writing
queries to access the data. Conceptual models are generally used as a data capture tool to gather
requirements. Often you see developers completely skip the creation of the conceptual model by going
right to the creation of the relational objects.
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