asked on

Best way to export data in searchable format from a datareader

I am buildig up a dynamic query that results in datareader being populated like follows........

while (thisReader.Read())
{
//do some kind of export stuff to CSV or EXEL -- let client download file to browser
}

...................................

So I want to be able to export the cotents of the datarader to ideally an CSV or EXCEL file. In addition I want just to strip out fields like firstname, lastname, address1, address2, postcode

Thanks

REA_ANDREW

Hwo about this?

            string filename = "YourDownload.csv";
            StringBuilder sb1 = new StringBuilder();
            using (StringWriter sw1 = new StringWriter(sb1))
            {
                sw1.Write(sda1.GetName(0) + "," + sda1.GetName(1) + "," + sda1.GetName(2));
                while (sda1.Read())
                {
                    sw1.WriteLine(sda1["Field1"] + "," + sda1["Field2"] + "," + sda1["Field3"]);
                }
                using (StreamWriter swr1 = File.CreateText(filename))
                {
                    sw1.WriteLine(sw1.ToString());
                    sw1.Flush();
                }
            }
            Response.Redirect(filename);

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mugsey

ASKER

Thanks for the reply - I will just test it out. So does this just push it to the browser?

mugsey

ASKER

Actually

The code snippet

string filename = "YourDownload.csv";

How could I get the user to type in the file name?

REA_ANDREW

ermm well say... OK say you have a textbox on your page so, 1 textbox, a label saying please input a filename and a button saying create a download.

You assign the filename as :

YourTextBox.Text +".csv";

Do you want it to simply redirect to a page and make sure a download screen appears and avoid it going into the browser?

If so I will drum up a working example for you which has a text box. That ok?

Let me know. :-)

Andrew

mugsey

ASKER

Hi Andew

Thanks a lot

Yes that would be great mate. Thanks again

mugsey

ASKER

I will try your example when I get home in about 2 hours - cheers !!!!!!!!

REA_ANDREW

Right OK here is the final version. Obviously just create your CSV using your while loop. For testing I have used a simple for loop, but you will see the logic and what is happening to achieve the download.

Cheers

Andrew

The ASP.NET Page
-----------------------------------
 
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Downloader.aspx.cs" Inherits="MVC_Prototype.Downloader" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:Label ID="Label1" runat="server" Text="Download"></asp:Label>
        <asp:TextBox ID="txtFilename" runat="server"></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="Create Download" OnClick="Button1_Click" />
    </div>
    </form>
</body>
</html>
 
 
C# Code
-----------------------------------
 
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Text;
 
namespace MVC_Prototype
{
    public partial class Downloader : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
 
        }
 
        protected void Button1_Click(object sender, EventArgs e)
        {
            string filename = txtFilename.Text+".csv";
            StringBuilder sb1 = new StringBuilder();
            using (StringWriter sw1 = new StringWriter(sb1))
            {
                sw1.WriteLine("Heading1" + "," + "Heading2" + "," + "Heading3");
                for (int i = 0; i < 100; i++)
                {
                    sw1.WriteLine("Andy" + "," + "Andy" + "," + "Andy");
                }
                Response.Clear();
                Response.AddHeader("content-disposition", "attachment;filename=" + filename);
                Response.Write(sw1.ToString());
            }
        }
    }
}

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Aurora27

either CSV or XML...XML is great for standard data sharing..its compatible and all...

CT.

mugsey

ASKER

Hi No it would need to be CSV

ASKER CERTIFIED SOLUTION

REA_ANDREW

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mugsey

ASKER

Sorry Andrew - been off work - YOU ARE A GENIOUS!!!!!!! Works great. Will post another related question now.

devtha

Andrew do you have a solution that will pick the fields from the screen (datareader?) and export it to excel? In your example you have hard coded values.