Create Pivot Table Excel sheet using SQL Server database in c#

i have created the sample .but not displaying any error but not Export to Excel Happening.



using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Microsoft.Office.Interop.Excel;
//using Microsoft.Office.Interop;
using System.Drawing;
using System.IO;
using System.Runtime.InteropServices;

using System.Collections;
using System.Text;
using System.Data;
using System.Reflection;





namespace WebApplication1
{
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
static object useDefault = Type.Missing;
protected void Button1_Click(object sender, EventArgs e)
{

//string workBookName = @"C:\temp\pivottablesample.xlsx";

string connection = @"OLEDB;Provider=SQLOLEDB.1;Integrated Security=SSPI;Data Source=178.10.10.200;Initial Catalog=Employee";

string command = "select * from EMP";

Microsoft.Office.Interop.Excel.Application app = new Microsoft.Office.Interop.Excel.Application();

Microsoft.Office.Interop.Excel.Workbook workbook = (Microsoft.Office.Interop.Excel.Workbook)app.Workbooks.Add(Type.Missing);


Microsoft.Office.Interop.Excel.PivotCache pivotCache = workbook.PivotCaches().Add(Microsoft.Office.Interop.Excel.XlPivotTableSourceType.xlExternal, Type.Missing);

pivotCache.Connection = connection;

pivotCache.MakeConnection();

pivotCache.MaintainConnection = true;

pivotCache.CommandText = command;

Microsoft.Office.Interop.Excel.Worksheet sheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.ActiveSheet;

pivotCache.CommandType = Microsoft.Office.Interop.Excel.XlCmdType.xlCmdSql;

Microsoft.Office.Interop.Excel.PivotTables pivotTables = (Microsoft.Office.Interop.Excel.PivotTables)sheet.PivotTables(Type.Missing);

Microsoft.Office.Interop.Excel.PivotTable pivotTable = pivotTables.Add(pivotCache, app.ActiveCell, "PivotTable1", Type.Missing, Type.Missing);

pivotTable.SmallGrid = false;
pivotTable.ShowTableStyleRowStripes = true;
pivotTable.TableStyle2 = "PivotStyleLight1";

Microsoft.Office.Interop.Excel.PivotField pageField = (Microsoft.Office.Interop.Excel.PivotField)pivotTable.PivotFields("EName");

pageField.Orientation = Microsoft.Office.Interop.Excel.XlPivotFieldOrientation.xlPageField;

Microsoft.Office.Interop.Excel.PivotField rowField = (Microsoft.Office.Interop.Excel.PivotField)pivotTable.PivotFields("EName");

rowField.Orientation = Microsoft.Office.Interop.Excel.XlPivotFieldOrientation.xlRowField;

pivotTable.AddDataField(pivotTable.PivotFields("ESalary"), "Sum of EmpSalary", Microsoft.Office.Interop.Excel.XlConsolidationFunction.xlSum);


//workbook.SaveAs(workBookName, useDefault, useDefault,
// useDefault, useDefault, useDefault,
// XlSaveAsAccessMode.xlNoChange, useDefault, useDefault,
// useDefault, useDefault, useDefault);


}


}
}