Update and Delete Data Using Code First Approach Fluent API

Vijay Prativadi
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Update Data using Code First Approach Fluent API

This article shows how to access a SQL Server database with the Entity Framework Code First Approach and later we will also look at how to do a update data operation.

Create an ASP.Net web application as in the following.

Employee.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace Update_Data_CFA___Fluent_API
{
public class Employee
{
public Employee()
{
}
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
}
}

Employeecontext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
namespace Update_Data_CFA___Fluent_API
{
public class EmployeeContext: DbContext
{
public EmployeeContext()
: base("EmployeeConn")
{
Database.SetInitializer<EmployeeContext>(new CreateDatabaseIfNotExists<EmployeeContext>());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Set primary key to Employee table
modelBuilder.Entity<Employee>().HasKey(m => m.Id).Property(m => m.Id).IsRequired();
//First Name is required and Max Length is 50
modelBuilder.Entity<Employee>().Property(p => p.FirstName).IsRequired().HasMaxLength(50);
//Last Name is required and Max Length is 50
modelBuilder.Entity<Employee>().Property(p => p.LastName).IsRequired().HasMaxLength(50);
//Age is required
modelBuilder.Entity<Employee>().Property(p => p.Age).IsRequired();
}
public DbSet<Employee> Employees { get; set; }
}
}

Web.config

<connectionStrings>
<add name="EmployeeConn"
connectionString="Data Source=WIN-B4KJ8JI75VF;Initial Catalog=EmployeeDB;Integrated Security=true"
providerName="System.Data.SqlClient"/>
</connectionStrings>

Webform1.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Update_Data_CFA___Fluent_API.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="Update Data CFA - Fluent API" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td>
<asp:Label ID="Label6" runat="server" Text="Please Enter Id: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox4" runat="server"></asp:TextBox>
</td>
</tr>
<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">
<asp:Button ID="Button1" runat="server" Text="Update Data"
BackColor="Orange" Font-Bold="true" OnClick="Button1_Click" />
<br />
<br />
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td colspan="3">
<asp:Label ID="Label5" runat="server" ForeColor="Red" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>

Webform1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Update_Data_CFA___Fluent_API
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
EmployeeContext empContext = new EmployeeContext();
var empId = int.Parse(TextBox4.Text);
var emp = empContext.Employees.Where(a => a.Id.Equals(empId)).SingleOrDefault();
emp.FirstName = TextBox1.Text;
emp.LastName = TextBox2.Text;
emp.Age = int.Parse(TextBox3.Text);
empContext.SaveChanges();
}
}
}

The output of the application looks as in the following.

Summary: In this operation we saw how to access a SQL Server database with the Entity Framework Code First Approach and how to do a update data operation. Happy coding.

Delete Data using Code First Approach Fluent API

In this operation we will see how to access a SQL Server database with the Entity Framework Code First Approach and later we will also look at how to do a delete data operation.

Create an ASP.Net web application as in the following.

Employee.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace Delete_Data_CFA___Fluent_API
{
public class Employee
{
public Employee()
{
}
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int Age { get; set; }
}
}

Employeecontext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
namespace Delete_Data_CFA___Fluent_API
{
public class EmployeeContext: DbContext
{
public EmployeeContext()
: base("EmployeeConn")
{
Database.SetInitializer<EmployeeContext>(new CreateDatabaseIfNotExists<EmployeeContext>());
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Set primary key to Employee table
modelBuilder.Entity<Employee>().HasKey(m => m.Id).Property(m => m.Id).IsRequired();
//First Name is required and Max Length is 50
modelBuilder.Entity<Employee>().Property(p => p.FirstName).IsRequired().HasMaxLength(50);
//Last Name is required and Max Length is 50
modelBuilder.Entity<Employee>().Property(p => p.LastName).IsRequired().HasMaxLength(50);
//Age is required
modelBuilder.Entity<Employee>().Property(p => p.Age).IsRequired();
}
public DbSet<Employee> Employees { get; set; }
}
}

Web.config

<connectionStrings>
<add name="EmployeeConn"
connectionString="Data Source=WIN-B4KJ8JI75VF;Initial Catalog=EmployeeDB;Integrated Security=true"
providerName="System.Data.SqlClient"/>
</connectionStrings>

Webform1.asp

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Delete_Data_CFA___Fluent_API.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="Delete Data CFA - Fluent API" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td>
<asp:Label ID="Label6" runat="server" Text="Please Enter Id: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td colspan="2">
<asp:Button ID="Button1" runat="server" Text="Delete Data"
BackColor="Orange" Font-Bold="true" OnClick="Button1_Click" />
<br />
<br />
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td colspan="3">
<asp:Label ID="Label5" runat="server" ForeColor="Red" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>

Webform1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Delete_Data_CFA___Fluent_API
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
EmployeeContext empContext = new EmployeeContext();
var empID = int.Parse(TextBox1.Text);
var emp = empContext.Employees.Where(a => a.Id.Equals(empID)).SingleOrDefault();
empContext.Employees.Remove(emp);
empContext.SaveChanges();
}
}
}

The output of the application looks as in the following.

Summary: In this operation we saw how to access a SQL Server database with the Entity Framework Code First Approach and how to do a delete data operation. Happy coding!

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