Hi nauna,

Refer below example.

For export to excel i have used ClosedXML. You can refer below article.

Export SQL data to Excel with Column Headers (Column Names) in C# and VB.Net

Database

For this example I have used of Northwind database that you can download using the link given below.

Download Northwind Database

Namespaces

C#

using System.Data;
using System.Linq;
using System.Reflection;

VB.Net

Imports System.Data
Imports System.Linq
Imports System.Reflection

Code

C#

protected void Page_Load(object sender, EventArgs e)
{
    NorthwindEntities db = new NorthwindEntities();
    var result = (from c in db.Customers
                    select new
                    {
                        Id = c.CustomerID,
                        Name = c.ContactName
                    }).ToList();
    DataTable dt = ToDataTable(result);
    using (ClosedXML.Excel.XLWorkbook wb = new ClosedXML.Excel.XLWorkbook())
    {
        wb.Worksheets.Add(dt, "Customers");

        Response.Clear();
        Response.Buffer = true;
        Response.Charset = "";
        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
        Response.AddHeader("content-disposition", "attachment;filename=Customers.xlsx");
        using (System.IO.MemoryStream MyMemoryStream = new System.IO.MemoryStream())
        {
            wb.SaveAs(MyMemoryStream);
            MyMemoryStream.WriteTo(Response.OutputStream);
            Response.Flush();
            Response.End();
        }
    }
}

public DataTable ToDataTable<T>(List<T> items)
{
    DataTable dataTable = new DataTable(typeof(T).Name);
    PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);
    foreach (PropertyInfo prop in Props)
    {
        dataTable.Columns.Add(prop.Name);
    }
    foreach (T item in items)
    {
        var values = new object[Props.Length];
        for (int i = 0; i < Props.Length; i++)
        {
            values[i] = Props[i].GetValue(item, null);
        }
        dataTable.Rows.Add(values);
    }
    return dataTable;
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
    Dim db As NorthwindEntities = New NorthwindEntities()
    Dim result = (From c In db.Customers
                    Select New With {
                    .Id = c.CustomerID,
                    .Name = c.ContactName
                }).ToList()
    Dim dt As DataTable = ToDataTable(result)

    Using wb As ClosedXML.Excel.XLWorkbook = New ClosedXML.Excel.XLWorkbook()
        wb.Worksheets.Add(dt, "Customers")
        Response.Clear()
        Response.Buffer = True
        Response.Charset = ""
        Response.ContentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"
        Response.AddHeader("content-disposition", "attachment;filename=Customers.xlsx")
        Using MyMemoryStream As System.IO.MemoryStream = New System.IO.MemoryStream()
            wb.SaveAs(MyMemoryStream)
            MyMemoryStream.WriteTo(Response.OutputStream)
            Response.Flush()
            Response.[End]()
        End Using
    End Using
End Sub

Public Function ToDataTable(Of T)(ByVal items As List(Of T)) As DataTable
    Dim dataTable As DataTable = New DataTable(GetType(T).Name)
    Dim Props As PropertyInfo() = GetType(T).GetProperties(BindingFlags.Public Or BindingFlags.Instance)
    For Each prop As PropertyInfo In Props
        dataTable.Columns.Add(prop.Name)
    Next
    For Each item As T In items
        Dim values = New Object(Props.Length - 1) {}
        For i As Integer = 0 To Props.Length - 1
            values(i) = Props(i).GetValue(item, Nothing)
        Next
        dataTable.Rows.Add(values)
    Next

    Return dataTable
End Function

Screenshot