I came across some nice libraries to use while programming to query Excel. Right now I’m am using the standard COM interface for my projects, which is fine for small ranges (which is true for most users – I would assume). But for large ranges I would need something more powerful.
LinqToExcel appears to be a great project for using a Linq interface to query Excel (but not write to Excel). It uses ADO under the hood to do the actual queries. This is great if you are using Excel 2007 or newer, but for 2003 and older you run into the problem of memory leaks when you query an open Excel document (which is what I usually do, I haven’t needed to get data from a closed document before) – see also.
Another problem I have found with this project is that if you need to interact with an Excel 64-bit install you will need to download extra software on the users computer. Not a huge deal, just extra work. I would imagine that you would be able to find code online that would help you automate the build process for you code for the two versions you would need to do. Currently I just rebuild the installer for x86 and x64 (one installer installs to 64-bit program folder, the other to 32-bit program folder).
EPPlus is another method to query and write to Excel (and supposedly faster). It only works with xml based Excel files though. So, EPPlus might be a nice library to use in the future if I decide to drop support for Excel 2003 and lower. But one of the nice things about NetOffice is that it is capable with working with older versions of excel.
This is a project I’m thinking about starting. I’ve done some work on it already. I would just need to clean it up and make it work as nice as LinqToExcel. It would be slower than both projects mentioned above, but, when you are working on small datasets it would come in handy.
I’ve read one of the best ways to learn how to code and improve your skills is by reading other people’s code. This would be a great opportunity for me to do just that!