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How to Use enum with Entity Framework 5 ?

, 26 Nov 2013
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This blog post shows how to use enum with Entity Framework 5.

What is enum?

  • The enum keyword is used to declare an enumeration
  • A distinct type consisting of a set of named constants called the enumerator list
  • Every enumeration type has an underlying type
  • The default underlying type of the enumeration elements is int
  • By default, the first enumerator has the value 0
  • And the value of each successive enumerator is increased by 1
  • EF 5 enum can have the Types as Byte, Int16, Int32, Int64 or SByte 
  • You can download the Source code Here from the Original Article 

Let's take a simple example  

E.g. 1 :

enum Days {Sat, Sun, Mon, Tue, Wed, Thu, Fri};

In this enumeration, Sat is 0, Sun is 1, Mon is 2, and so forth

E.g. 2 : Enumerators can have initializers to override the default values 

enum Days {Sat=1, Sun, Mon, Tue, Wed, Thu, Fri};

In this enumeration, the sequence of elements is forced to start from 1 instead of 0

How to Use enum with Entity Framework 5 Code First ?

  • This feature is Latest improvement of EF 5

Step 1 : Open Visual Studio 2012

Step 2 : File ==> New Project as EF5EnumSupport

New Project as EF5EnumSupport

Step 3 : Right Click Your Solution and then Click Manage NuGet Packages...

Manage NuGet Packages

Step 4 : Click Online Tab and Then Type Entity Framework 5 on Search Box

After that Select EntityFramework and Click Install

Select EntityFramework

Step 5 : Click I Accept

Click I Accept

After the above Step, below mentioned DLLs (Red Color) have added to the Project

DLLs (Red Color)  have added to the Project

Step 6 : Add ==> New Class and make it as enum Type Course

Solution Explorer 

Complete project

Course.cs  

namespace EF5EnumSupport.Models
 {
    public enum Course
    {
        Mcsd = 1,
        Mcse,
        Mcsa,
        Mcitp
    }
 }

 

Step 7 : Add ==> New Class as Student

Student.cs

 namespace EF5EnumSupport.Models {
    public class Student
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public Course Course { get; set; }
    }
 }

Step 8 : Create DbContext derived Class as StudentContext

StudentContext.cs

 using System.Data.Entity;
 namespace EF5EnumSupport.Models
 {
    public class StudentContext : DbContext
    {
        public DbSet<Student> Students { get; set; }
    }
 }

 

Step 9 : Console application's Main Method is as below

Program.cs

using System;
using System.Linq;
using EF5EnumSupport.Models;
namespace EF5EnumSupport
{
  public class Program
  {
     static void Main(string[] args)
     {
       using (var context = new StudentContext())
       {
        context.Students.Add(new Student { Name = "Sampath Lokuge",
        Course = Course.Mcsd });
        context.SaveChanges();
         var studentQuery = (from d in context.Students
                             where d.Course == Course.Mcsd
                             select d).FirstOrDefault();
         if (studentQuery != null)
          {
           Console.WriteLine("Student Id: {0} Name: {1} Course : {2}",
               studentQuery.Id, studentQuery.Name,
               studentQuery.Course);           }
         }
     }
  }
}

 

The brand new enum support allows you to have enum properties in your entity classes

enum properties in your entity classes

 

Step 10 : Run the Console Application

DEBUG ==> Start Without Debugging (Ctrl + F5)

Run the Console Application

 

Step 11 : Where's the Database ?

  • By default the database will be created on the LocalDB instance
  • The Entity Framework names the database after the fully qualified name of the derived context
  • i.e. EF5EnumSupport.Models.StudentContext

    SQL Server Object Explorer in Visual Studio 2012 is as below

    SQL Server Object Explorer in Visual Studio 2012

 

View Data on Students Table

View Data on Students Table

 

What is LocalDb ?

  • Microsoft SQL Server 2012 Express LocalDB is an execution mode of SQL Server Express targeted to program developers
  • LocalDB installation copies a minimal set of files necessary to start the SQL Server Database Engine

That's It.You're Done.

Conclusion

  • Entity Framework 5 brings a number of improvements and enum Support in Code First is one of them
  • You can see that when you use enum type with your model class, Visual Studio 2012 gives intellisense support out of the box
  • It's really awesome new feature of the Entity Framework 5
  • So Enjoy it

I hope this helps to you. Comments and feedback greatly appreciated. 

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

About the Author

Sampath Lokuge
Software Developer (Senior) Freelancer
Sri Lanka Sri Lanka
Sampath Lokuge holds a Bachelor of Science degree in the Mathematics and Computer Science at the University of Colombo, Sri Lanka.
 
He possesses over 7 years of experience in constructing web applications using Microsoft Technologies including ASP.net MVC, C#, SQL Server, Web API, Entity Framework and also other web technologies such as HTML5, CSS3,jQuery and AngularJS.
 
Sampath has earned Microsoft certifications such as MCP, MCAD, MCSD and MCTS and very recently he has completed MS (Microsoft Specialist) for MVC 4 and MCSD (Windows Store Apps Using HTML5).
 
Besides that, he is an active blogger, writing about web and mobile development issues and promoting best practices.He also actively participates in online communities such as Code Project and StackOverflow.He himself is handling three communities, which are ASP.net MVC 5 With C# on Linkedin,Entity Framework 6 on G+ and Hybrid Mobile App with WinJS on Facebook.
 
My Email : sugeesampathlokuge@gmail.com

My Tech Blog

Sampath Lokuge Tech Blog

Communities which I'm Handling :

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