Introduction
Today, in this article let's play around with one of the interesting and most useful concepts in LINQ.
Question: What is adding migration entities?
In simple terms "It enables creation of a database structure and performs database migrations for adding a new property or updating the database structure".
Step 1: Create a new web application
![Output1.jpg]()
Step 2: The complete code of Student.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace AddMigrationsApp
{
public class Student
{
public int Id
{
get;
set;
}
public string FirstName
{
get;
set;
}
public string LastName
{
get;
set;
}
public int Age
{
get;
set;
}
public string Location
{
get;
set;
}
}
}
Step 3: The complete code of StudentContext.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
namespace AddMigrationsApp
{
public class StudentContext : DbContext
{
public DbSet<Student> Students
{
get;
set;
}
}
}
Step 4: The complete code of WebForm1.aspx looks like this:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="AddMigrationsApp.WebForm1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<center>
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="Insert Data Add Migration" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td>
<asp:Label ID="Label2" runat="server" Text="Please Enter FirstName: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label3" runat="server" Text="Please Enter LastName: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label4" runat="server" Text="Please Enter Age: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="Button1" runat="server" Text="Insert Data" OnClick="Button1_Click"
BackColor="Orange" Font-Bold="true" /><br />
<br />
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td colspan="3">
<asp:Label ID="Label5" runat="server" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
</center>
</div>
</form>
</body>
</html>
Step 5: The complete code of WebForm1.aspx.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace AddMigrationsApp
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
if
(string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text) || string.IsNullOrEmpty(TextBox3.Text))
{
Label5.Text = "Please Enter Some Values";
Label5.ForeColor = System.Drawing.Color.Red;
}
else
{
var addStudent = new Student
{
FirstName = TextBox1.Text,
LastName = TextBox2.Text,
Age = Convert.ToInt32(TextBox3.Text)
};
objContext.Students.Add(addStudent);
objContext.SaveChanges();
Label5.Text = "Data Successfully Inserted";
Label5.ForeColor = System.Drawing.Color.Green; TextBox1.Text = string.Empty;
TextBox2.Text = string.Empty; TextBox3.Text = string.Empty;
}
}
#region Instance MembersStudentContext objContext = new StudentContext();
#endregion
}
}
Step 6: The output of the application looks like this:
![Output2.png]()
Step 7: The inserted data output of the application looks like this:
![Output3.png]()
Step 8: The database created output of the application looks like this:
![Output4.png]()
Step 9: The enabling migrations output of the application looks like this:
![Output5.png]()
Step 10: The adding new property migrations output of the application looks like this:
![Output6.png]()
Step 11: The update database migrations output of the application looks like this:
![Output7.png]()
Step 12: The database updated output of the application looks like this:
![Output8.png]()
I hope this article was useful for you.