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.