Guide to Entity Framework with

create
, 
read
, 
update
, and 
delete
(
CRUD
) 
operations, the Object Services Layer provides the following additional services:
• 
Change tracking
• 
Lazy loading
• 
Inheritance
• 
Optimistic concurrency
• 
Merging data
• 
Identity resolution
• 
Support for querying data using Entity SQL and LINQ to Entities
You will learn more about Object Services later in the book. The Object Services 
Layer leverages an 
Object Query
object internally to process the data. Note that
the Object Services Layer supports querying data using both Entity SQL and LINQ
to Entities.
Features and benefits at a glance
Here is a quick look at some of the features and benefits of Entity Framework:
• 
It provides support for an increased level of abstraction on top of the 
underlying data store
• 
It provides support for extensibility and seamless querying of data using 
Entity SQL and LINQ
• 
It is a flexible schema that can be used to store the mapping information
• 
There is a reduction in the amount of 
Kilo Lines of Code
(
KLOC
) needed
to write data access code in your applications
• 
It contains a powerful Object Services Layer
• 
It provides support for a full text-based query language
• 
It provides support for persistence ignorance
• 
IT provides support for lazy loading
KLOC refers to Kilo Lines of Code, a unit of measuring the amount of 
source code in your programs.

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Introducing the ADO.NET Entity Framework
[
 22 
]
System requirements
To run the programs given in this book, you should have the following elements 
installed on your system:
• 
Visual Studio.NET 2012 or higher
• 
SQL Server 2014 or higher
Entity Framework 6.0 can be downloaded from NuGet at
https://entityframework.codeplex.com/
releases/view/87028
.
Note that Entity Framework 6.0 already ships with Visual Studio 2013, so there is no 
need to download it if you use this version of Visual Studio.
Now let's take a quick look at each of these new features. We will explore each of 
these features in detail as we move through the chapters.