Question

I would like to export data from a SQL Server pull (usually I use SqlDataReader, but am open to suggestions) into an Excel/CSV file and have the user of the web app get it as a download.

I’d like to do this AJAX style, so that the click on download won’t cause a reload/postback.

Anyone done this before or have an idea on how?

Answer 1

I think this mechanism would work.

Have an HTML button that calls a javascript function when clicked.

<input id="downloadbtn" type="button" value="Download" onclick="download();" />

Function would look something like this:

var download = function() {
  $.ajax({
  url: "datamaker.aspx",
  context: document.body
  }).done(function(data) { 
    //  parse response data, get file path
    var filepath = ParseDataToGetFilePath(data);

    // open the csv file path in a new window (which will begin download)
    window.open(filepath, '_blank');
  });

};

In the serverside, “datamaker.aspx” should connect to the SQL Server, and create the CSV file. Creating a CSV file is as easy as creating any other file using streamwriter, and writiing “comma” between fields. At the end of this page, output the filename either in a response xml or json.

     { filepath: \path\datafile.csv }