Guide to Entity Framework with

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In the model-first approach, you create your entities, relationships, and the inheritance 
hierarchies directly on the design surface of the EDM Designer in Visual Studio and 
then generate the database from the model designed. If you need additional features, 
you can use partial classes. In essence, in this approach, the model drives and defines 
the database. This is also known as the 
model-driven approach
. This approach is good 
for small projects, but with complex databases and large projects this is not a preferred 
approach as you don't have much control over the database. Also, making manual 
changes to the database schema is also not recommended.
In the database-first approach, you would create your database first and then 
generate your model using the ADO.NET EDM Designer from this database.
Support for built-in functions and UDF 
support
Entity Framework 6 provides support for you to use SQL Server functions directly in 
your queries. Here is an example:
from emp in PayrollDataContext.Employee
where new[] {"january","february","march"}.Contains(SqlFunctions.
DateName("mon
th", emp.JoiningDate))
orderby emp.EmployeeID
select new 
{
emp.EmployeeID,emp.JoiningDate
};
Support for model-defined functions
Entity Framework 6 now provides
support for model-defined functions that can be 
defined in the CSDL using eSQL. Note that model-defined functions support LINQ 
to Entities and can also be called Object methods. Here is an example:


Edm.DiffYears(Employee.BirthDate, Edm.CurrentDateTime())

.
In this section, we just gave you an introduction to the new features in Entity 
Framework 6—we will cover details of each of these features in the forthcoming 
chapters of this book.

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Introducing the ADO.NET Entity Framework