Delete and Update Data in Reverse Engineering POCO Generator

Vijay Prativadi
Feb 18, 2013

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Delete Data - Reverse Engineering POCO Generator

Introduction

This article demonstrates an interesting and very useful concept in Entity Framework.

Question: What is the reverse engineering POCO generator?

In simple terms "It is a template that enables generation of entity classes by reverse engineering with the POCO generator".

Step 1: Create a new web application

Step 2: Adding a new Entity Framework reverse engineering POCO generator :

Step 3: The complete code of WebForm1.aspx is as in the following:

<%@Page Language="C#"AutoEventWireup="true"CodeBehind="WebForm1.aspx.cs"Inherits="DeleteDataReverseEnggPOCOGenerator.WebForm1"%>

<!DOCTYPE htmlPUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<formid="form1"runat="server">

<div>

<table>

<tr>

<tdcolspan="2"align="center">

<asp:LabelID="Label1"runat="server"Text="Delete Data - Reverse Engg. POCO Generator"

Font-Bold="true"Font-Size="Large"Font-Names="Verdana"ForeColor="Maroon"></asp:Label>

</td>

</tr>

<tr>

<td>

<asp:LabelID="Label2"runat="server"Text="Please Enter Employee Id" ForeColor="Brown"

Font-Bold="true"Font-Size="Medium"Font-Names="Verdana"></asp:Label>

</td>

<td>

<asp:TextBoxID="TextBox1"runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<tdcolspan="2"align="center">

<asp:ButtonID="Button1"runat="server"Text="Delete Data"Font-Names="Verdana"Width="213px"

BackColor="Orange"Font-Bold="True"OnClick="Button1_Click"/>

</td>

</tr>

<tr>

<tdcolspan="2"align="center">

<asp:LabelID="Label3"runat="server"Font-Bold="true"Font-Size="Medium"Font-Names="Verdana"></asp:Label>

</td>

</tr>

</table>

</div>

</center>

</form>

</body>

</html>

Step 4: The complete code of WebForm1.aspx.cs is as in the following:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace DeleteDataReverseEnggPOCOGenerator

{

publicpartial classWebForm1 : System.Web.UI.Page

{

protectedvoid Page_Load(object sender, EventArgs e)

{

}

protectedvoid Button1_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text))

{

Label3.Text ="Please Enter Some Values";

Label3.ForeColor = System.Drawing.Color.Red;

}

else

{

int id = int.Parse(TextBox1.Text);

var query = (from r in objEntities.TblEmployee where r.EmpId == idselect r).Single();

objEntities.TblEmployee.Remove(query);

objEntities.SaveChanges();

Label3.Text ="Data Deleted Successfully";

Label3.ForeColor = System.Drawing.Color.Green;

TextBox1.Text =string.Empty;

}

#region Instance MembersMyDbContext objEntities = new MyDbContext();

#endregion

}

Step 5: The complete code of web.config is as in the following:

<?xml version="1.0"encoding="utf-8"?>

<sectionname="entityFramework"type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=4.4.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"requirePermission="false" />

</configSections>

<addname="ApplicationServices"connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\aspnetdb.mdf;User Instance=true" providerName="System.Data.SqlClient" />

<addname="MyDbContext"connectionString="Data Source=WIN-KV3BO1RQQF7;Initial Catalog=Company;Integrated Security=True;MultipleActiveResultSets=True" providerName="System.Data.SqlClient" />

</connectionStrings>

<system.web>

<compilationdebug="true"targetFramework="4.0" />

<authenticationmode="Forms">

<formsloginUrl="~/Account/Login.aspx"timeout="2880" />

</authentication>

<addname="AspNetSqlMembershipProvider"type="System.Web.Security.SqlMembershipProvider"connectionStringName="ApplicationServices"enablePasswordRetrieval="false"enablePasswordReset="true"requiresQuestionAndAnswer="false"requiresUniqueEmail="false"maxInvalidPasswordAttempts="5"minRequiredPasswordLength="6"minRequiredNonalphanumericCharacters="0"passwordAttemptWindow="10"applicationName="/" />

</providers>

</membership>

<addname="AspNetSqlProfileProvider"type="System.Web.Profile.SqlProfileProvider"connectionStringName="ApplicationServices"applicationName="/" />

</providers>

</profile>

<roleManagerenabled="false">

<addname="AspNetSqlRoleProvider"type="System.Web.Security.SqlRoleProvider"connectionStringName="ApplicationServices"applicationName="/" />

<addname="AspNetWindowsTokenRoleProvider"type="System.Web.Security.WindowsTokenRoleProvider"applicationName="/" />

</providers>

</roleManager>

</system.web>

<system.webServer>

<modulesrunAllManagedModulesForAllRequests="true" />

</system.webServer>

<defaultConnectionFactorytype="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />

</entityFramework>

</configuration>

Step 6: The output of the application is as in the following:

Step 7: The deleted data output of the application is as in the following:

Update Data - Reverse Engineering POCO Generator

Question: What is reverse engineering POCO generator?

In simple terms "It is a template that enables generation of entity classes by reverse engineering with the POCO generator".

Step 1: Create a new web application

Step 2: Adding a new Entity Framework reverse engineering POCO generator:

Step 3: The complete code of WebForm1.aspx is as in the following:

<%@Page Language="C#"AutoEventWireup="true"CodeBehind="WebForm1.aspx.cs"Inherits="UpdateDataReverseEnggPOCOTemplate.WebForm1"%>

<!DOCTYPE htmlPUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

</head>

<body>

<formid="form1"runat="server">

<div>

<table>

<tr>

<tdcolspan="2">

<asp:LabelID="Label1"runat="server"Text="Update Data - Reverse Engg. POCO Generator"

Font-Bold="true"Font-Size="Large"Font-Names="Verdana"ForeColor="Maroon"></asp:Label>

</td>

</tr>

<tr>

<td>

<asp:LabelID="Label6"runat="server"Text="Please Enter Id" Font-Size="Large"Font-Names="Verdana"

Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBoxID="TextBox4"runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:LabelID="Label2"runat="server"Text="Please Enter First Name" Font-Size="Large"

Font-Names="Verdana"Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBoxID="TextBox1"runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:LabelID="Label3"runat="server"Text="Please Enter Last Name" Font-Size="Large"

Font-Names="Verdana"Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBoxID="TextBox2"runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<td>

<asp:LabelID="Label4"runat="server"Text="Please Enter Age" Font-Size="Large"Font-Names="Verdana"

Font-Italic="true"></asp:Label>

</td>

<td>

<asp:TextBoxID="TextBox3"runat="server"></asp:TextBox>

</td>

</tr>

<tr>

<tdcolspan="2"align="center">

<asp:ButtonID="Button1"runat="server"Text="Update"Font-Names="Verdana"Width="213px"

BackColor="Orange"Font-Bold="True"OnClick="Button1_Click"/>

</td>

</tr>

<tr>

<tdcolspan="2"align="center">

<asp:LabelID="Label5"runat="server"Font-Bold="true"Font-Names="Verdana"ForeColor="Maroon"></asp:Label>

</td>

</tr>

</table>

</div>

</center>

</form>

</body>

</html>

Step 4: The complete code of WebForm1.aspx.cs is as in the following:

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

namespace UpdateDataReverseEnggPOCOTemplate

{

publicpartial classWebForm1 : System.Web.UI.Page{protectedvoid Page_Load(object sender, EventArgs e)

{

}

protectedvoid Button1_Click(object sender, EventArgs e)

{

if (string.IsNullOrEmpty(TextBox1.Text) || string.IsNullOrEmpty(TextBox2.Text) ||string.IsNullOrEmpty(TextBox3.Text) ||string.IsNullOrEmpty(TextBox4.Text))

{

Label5.Text ="Please Enter Some Data";

Label5.ForeColor = System.Drawing.Color.Red;

}

else

{

var id1 = Convert.ToInt32(TextBox4.Text);

var objEmployee = objEntities.TblEmployee.Where(a => a.EmpId == id1).FirstOrDefault();

objEmployee.FirstName = TextBox1.Text;

objEmployee.LastName = TextBox2.Text;

objEmployee.Age =int.Parse(TextBox3.Text);

objEntities.SaveChanges();

Label5.Text ="Data Updated Successfully";

Label5.ForeColor = System.Drawing.Color.Green;

TextBox1.Text =string.Empty;

TextBox2.Text =string.Empty;

TextBox3.Text =string.Empty;TextBox4.Text =string.Empty;

}

#region Instance MembersMyDbContext objEntities = new MyDbContext();

#endregion

}

Step 5: The complete code of web.config is as in the following:

<?xml version="1.0"encoding="utf-8"?>

</configSections>

<addname="MyDbContext"connectionString="Data Source=WIN-KV3BO1RQQF7;Initial Catalog=Company;Integrated Security=True;MultipleActiveResultSets=True" providerName="System.Data.SqlClient" />

</connectionStrings>

<system.web>

<compilationdebug="true"targetFramework="4.0" />

<authenticationmode="Forms">

<formsloginUrl="~/Account/Login.aspx"timeout="2880" />

</authentication>

</providers>

</membership>

<addname="AspNetSqlProfileProvider"type="System.Web.Profile.SqlProfileProvider"connectionStringName="ApplicationServices"applicationName="/" />

</providers>

</profile>

<roleManagerenabled="false">

<addname="AspNetSqlRoleProvider"type="System.Web.Security.SqlRoleProvider"connectionStringName="ApplicationServices"applicationName="/" />

<addname="AspNetWindowsTokenRoleProvider"type="System.Web.Security.WindowsTokenRoleProvider"applicationName="/" />

</providers>

</roleManager>

</system.web>

<system.webServer>

<modulesrunAllManagedModulesForAllRequests="true" />

</system.webServer>

<defaultConnectionFactorytype="System.Data.Entity.Infrastructure.SqlConnectionFactory, EntityFramework" />

</entityFramework>

</configuration>

Step 6: The output of the application is as in the following:

Step 7: The updated data output of the application is as in the following:

I hope this article was useful for you. I look forward to your comments and feedback. Thanks Vijay.

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