Conditional Mapping in entity framework with code first

I Explained before that Conditional mapping in Entity Framework means When we want only a portion of data From database or table according to a condition then for fulfil this situation we use Conditional Mapping in EntityFramework.

Here we will learn Conditional mapping in Entity Framework with code first Approach.

Step 1: Create a new web application And install Entity framework..

Step 2: Add a class to the project. Give the Name as Student.cs. Write Below code.

namespace EFTableSplitting {     public class Student     {         public int StudentID { get; set; }         public string FirstName { get; set; }         public string LastName { get; set; }         public string Gender { get; set; }           public bool IsDiscard s{ get; set; }     } }

Step 3: Add a class to the project For the DBContext and give the name  it asStudentDBContext.cs. And Write below code.

using System.Data.Entity; namespace EFTableSplitting {     public class StudentDBContext : DbContext     {         public DbSet<Student> Students { get; set; }         protected override void OnModelCreating(DbModelBuilder _Modal)         {            _Modal.Entity<Student>()                 .Map(c => c.Requires("IsDiscard")                 .HasValue(false))                 .Ignore(c => c.IsDiscard);             base.OnModelCreating(_Modal);         }     } }

Step 4: Add the database connection string in web.config file.

<connectionStrings>   <add name="StudentDBContext"       connectionString="server=.; database=entitysplitting; integrated security=SSPI;"       providerName="System.Data.SqlClient" /> </connectionStrings>

Step 5: Add a webform to the project. Go to Tool Box and Drag and drop a GridView control. 

<asp:GridView ID="GridView1" runat="server">     </asp:GridView> s

Step 6: Write below code at page load event.

protected void Page_Load(object sender, EventArgs e) {     StudentDBContext studentDBContext = new StudentsDBContext();     GridView1.DataSource = studentDBContext.Students.ToList();     GridView1.DataBind(); }

Step 7: If you already have entitysplitting database in SQL Server. Delete it first

And then Run the application.

Step 8: At this point, run the application. entitysplitting database and Student table should be created by the entity framework.

Step 9: Insert data using the following SQL script

Insert into Students values ('Munesh', 'Sharma', Male',m@g.com,5555555555) Insert into Students values ('Rahul', 'Sharma', 'Male',R@g.com,333333333) Insert into Students values ('Sara', 'vilium', 'Female',S@g.com,111111111) Insert into Students values ('Mark', 'hash', 'Female',M1@g.com,2222222222) Insert into Students values ('ABC', 'EFG', 'Male',A@g.com,6666666666)