Entity Framework 5.0 API是分布在两个地方：NuGet和.NET Framework中，这个.NET framework 4.0/4.5包含EF核心的API，然而通过NuGet包获取的EntityFramework.dll包含EF 5.0特别的特性；EF6.0中不是分开的：
Entity Framework 5.0 API was distributed in two places, in NuGet package and in .NET framework. The .NET framework 4.0/4.5 included EF core API, whereas EntityFramework.dll via NuGet package included EF 5.0 specific features.
This has been changed with EF 6.0 which is included in EntityFramework.dll only and is not dependent on .NET framework.
For the basic tutorials, we will use EF 6.0, the latest version of entity framework as of this writing.
Install the following tools to work with entity framework:
- .NET Framework 4.5
- Visual Studio 2012
- MS SQL Server 2005/2008/2012 Express
在这个基础的系列课程中，我将会使用EF 6.0，这个最新的EF版本来学习，
学习EF，首先要安装下面的工具：
.NET Framework 4.5
Visual Studio 2012/2013/2015
MS SQL Server2005/2008/2012/2014 Express
下面我们来看看怎么安装EF吧：
我们打开VS2012新建项目：
然后，我们选中“项目名称”，点击右键，选择“管理Nuget程序包”，在弹出来的界面中，输入："EntityFramework",会自动查询到EntityFramework，然后点击安装，按照我下面的图示进行就可以了：
安装完成之后，是这样的：然后关闭这个窗口就行了。。。
创建数据库：
这个系列课程中，我将会使用SchoolDB样例数据库，它包含数据表，存储过程，和视图；数据库的设计如下：
You can see in the above diagram that the sample SchoolDB database includes tables with the following relationships, for demo purpose.
- One-to-One: Student and StudentAddress have a one-to-one relationship eg. Student has zero or one StudentAddress.
- One-to-Many: Standard and Teacher have a one-to-many relationship eg. many Teachers can be associate with one Standard.
- Many-to-Many: Student and Course have a many-to-many relationship using StudentCourse table where StudentCourse table includes StudentId and CourseId. So one student can join many courses and one course also can have many students.
Download Sample Project for all the tutorials on entity framework.
Let's create first simple Entity Data Model for sample School database in the next section.