In this article I will explain with an example, how to export Grid (Html Table) data from database to CSV (Text) file in ASP.Net Core MVC.
The Grid (Html Table) will be populated from database using Entity Framework and then the records from the database will be exported and downloaded as Microsoft CSV (Text) file in ASP.Net Core MVC.
 
 
Database
Here I am making use of Microsoft’s Northwind Database. You can download it from here.
 
 
Namespaces
You need to import the following namespaces.
using System.Text;
using Microsoft.AspNetCore.Http;
 
 
Model
The Model class consists of the following four properties.
public class Customer
{
    public string CustomerID { get; set; }
    public string ContactName { get; set; }
    public string City { 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.
Note: For beginners in ASP.Net Core and Entity Framework, please refer my article ASP.Net Core: Simple Entity Framework Tutorial with example. It covers all the information needed for connecting and configuring Entity Framework with ASP.Net Core.
 
using Microsoft.EntityFrameworkCore;
 
namespace Export_CSV_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, the Top 10 records are fetched from the Customers table using Entity Framework and returned to the View.
 
Action method for handling the CSV (Text) file Export and Download operation
This Action method is executed when the Export Button is clicked.
Note: The following Action method performs File Download operation. Hence the return type is set to FileResult.
 
Inside this Action method, the Top 10 records are fetched from the Customers Table using Entity Framework.
Then, a loop is executed over the records fetched using Entity Framework and a comma separated (delimited) string is generated which is ultimately converted to a Byte Array using the GetBytes method of Encoding class.
Finally, the Byte Array is exported and downloaded as CSV (Text) file using the File function.
public class HomeController : Controller
{
    private DBCtx Context { get; }
 
    public HomeController(DBCtx _context)
    {
        this.Context = _context;
    }
 
    public IActionResult Index()
    {
        return View(this.Context.Customers.Take(10).ToList());
    }
 
    [HttpPost]
    public FileResult Export()
    {
        string[] columnNames = new string[] { "CustomerId", "ContactName", "City", "Country" };
        var customers = this.Context.Customers.Take(10).ToList();
 
        //Build the CSV file data as a Comma separated string.
        string csv = string.Empty;
 
        foreach (string columnName in columnNames)
        {
            //Add the Header row for CSV file.
            csv += columnName + ',';
        }
 
        //Add new line.
        csv += "\r\n";
 
        foreach (var customer in customers)
        {
            //Add the Data rows.
            csv += customer.CustomerID.Replace(",", ";") + ',';
            csv += customer.ContactName.Replace(",", ";") + ',';
            csv += customer.City.Replace(",", ";") + ',';
            csv += customer.Country.Replace(",", ";") + ',';
 
            //Add new line.
            csv += "\r\n";
        }
 
        //Download the CSV file.
        byte[] bytes = Encoding.ASCII.GetBytes(csv);
        return File(bytes, "text/csv", "Grid.csv");
    }
}
 
 
View
Inside the View, in the very first line the Customer Model is declared as IEnumerable which specifies that it will be available as a Collection.
Displaying the Records
For displaying the records, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the Customer records.
 
Exporting HTML Table to CSV (Text) file
Below the HTML Table there is an HTML Form created with following ASP.Net Tag Helpers attributes.
asp-action – Name of the Action. In this case the name is Export.
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 Form consists of a Submit Button.
When the Export Button is clicked, the Grid (Html Table) data will be exported and downloaded as CSV (Text) file.
@model IEnumerable<Export_CSV_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>
    <h4>Customers</h4>
    <hr/>
    <div id="Grid">
        <table cellpadding="5" cellspacing="0" style="border: 1px solid #ccc; font-size: 9pt; font-family:Arial">
            <tr>
                <th style="background-color: #B8DBFD;border: 1px solid #ccc">CustomerID</th>
                <th style="background-color: #B8DBFD;border: 1px solid #ccc">ContactName</th>
                <th style="background-color: #B8DBFD;border: 1px solid #ccc">City</th>
                <th style="background-color: #B8DBFD;border: 1px solid #ccc">Country</th>
            </tr>
            @foreach (var customer in Model)
            {
                <tr>
                    <td style="width:120px;border: 1px solid #ccc">@customer.CustomerID</td>
                    <td style="width:120px;border: 1px solid #ccc">@customer.ContactName</td>
                    <td style="width:120px;border: 1px solid #ccc">@customer.City</td>
                    <td style="width:120px;border: 1px solid #ccc">@customer.Country</td>
                </tr>
            }
        </table>
    </div>
    <br/>
    <br/>
    <form method="post" asp-action="Export" asp-controller="Home">
        <input type="submit" id="btnSubmit" value="Export" />
    </form>
</body>
</html>
 
 
Screenshots
Grid (Html Table)
ASP.Net Core MVC: Export Grid (Html Table) data from database to CSV (Text) file
 
Exported CSV (Text) file
ASP.Net Core MVC: Export Grid (Html Table) data from database to CSV (Text) file
 
 
Downloads