So I’m trying to get the results from a stored proc (200k rows+) into an Excel file from ASP.NET but having a few difficulties. I don’t think csv is an option as the client want the numbers formatted correctly. I’ve tried three third party Excel libraries but all have fallen over with so much data and are using gigabytes of memory.
I’ve wrote some code to generate an Excel XML file and it runs very quickly but the file is over 300megs. If I open and save as a native Excel file it gets it down to 30megs. At the moment my best solution is to zip this xml file on the server which gets it down to 7megs but the user is still going to end up with a huge file once unzipped. Ideally I’d like to find a third party Excel library that can write a native Excel file with 200,000+ rows without killing the server, any ideas?
I ended up generating a xlsx myself, it turns out the format is pretty simple