In this article I will explain with an example, how to delete data from Database using Entity Framework in ASP.Net Core MVC.
Database
I have made use of the following table Customers with the schema as follows. CustomerId is an Auto-Increment (Identity) column.
I have already inserted few records in the table.
Note: You can download the database table SQL by clicking the download link below.
Model
Following class is used as the Model class.
public class Customer
{
public int CustomerId { get; set; }
public string Name { get; set; }
public string Country { get; set; }
}
Database Context
Once the Entity Framework is configured and connected to the database table, the Database Context will look as shown below.
using Microsoft.EntityFrameworkCore;
namespace EF_Delete_MVC_Core
{
public class DBCtx : DbContext
{
public DBCtx(DbContextOptions<DBCtx> options) : base(options)
{
}
public DbSet<Customer> Customers { get; set; }
}
}
Controller
The Controller consists of following two Action methods.
Action method for handling GET operation
Inside this Action method, simply the View is returned.
Action method for handling POST operation
Inside this Action method, the Customer object is received as parameter.
The CustomerId value of the received Customer object is used to reference the Customer record using Entity Framework.
Once the record is referenced, the Customer record is deleted from the Customers table and a message is set in a ViewBag object.
public class HomeController : Controller
{
private DBCtx Context { get; }
public HomeController(DBCtx _context)
{
this.Context = _context;
}
public IActionResult Index()
{
return View();
}
[HttpPost]
public IActionResult Index(Customer customer)
{
Customer deletedCustomer = (from c in this.Context.Customers
where c.CustomerId == customer.CustomerId
select c).FirstOrDefault();
if (deletedCustomer != null)
{
this.Context.Customers.Remove(deletedCustomer);
this.Context.SaveChanges();
ViewBag.Message = "Customer record deleted.";
}
else
{
ViewBag.Message = "Customer not found.";
}
return View();
}
}
View
Inside the View, in the very first line the Customer Model class is declared as Model for the View.
The View consists of an HTML Form which has been created using following Tag Helpers attributes.
asp-action – Name of the Action. In this case the name is Index.
asp-controller – Name of the Controller. In this case the name is Home.
method – It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.
The HTML Form consists of a TextBox and a Submit Button.
When the Delete button is clicked, the value of CustomerId is passed to the Controller’s Action method.
Finally, the value of the ViewBag object is displayed using JavaScript Alert Message Box.
@model EF_Delete_MVC_Core.Models.Customer
@addTagHelper*, Microsoft.AspNetCore.Mvc.TagHelpers
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
</head>
<body>
<form method="post" asp-action="Index" asp-controller="Home">
<table border="0" cellpadding="0" cellspacing="0">
<tr>
<td style="width: 60px">
Id<br />
<input type="text" asp-for="CustomerId" style="width:50px" />
</td>
<td style="width: 200px">
<br />
<input type="submit" id="btnDelete" value="Delete" />
</td>
</tr>
</table>
</form>
@if (ViewBag.Message != null)
{
<script type="text/javascript">
window.onload = function () {
alert("@ViewBag.Message");
};
</script>
}
</body>
</html>
Screenshot
Downloads