Comparing two excel files

Question

I'm in the process of developping a tool to compare two excel files.

One excel file contains around 300-400 rows. In each excel file there are 4 tables with different number of columns. tables are aligned one after the other in one sheet.

I tried using couple of excel comparison tool like Beyond Compare, TestComplete and ExcelCompare macro from source forge. But none did work. I think it's because the file contains different tables. So I planned to develop a tool to compare excel files.But according to my research it is not a simple task :)

My approach is to extract 2 rows from the 2 excel files (1st row from A.xlsx and first row from B.xlsx) at a time , put the values into sperate 2 arrays and then compare the values . Identify the different values and write it back to a new Excel file.

Is this approach efficient or suitable for a file with 300 rows...??? If anyone have a different and a simple idea please share with me.

I'm planning to use C# and Excel 2010 for the development.

Any help is appreciated :)

Answer 1

My approach would be to convert both sheets to CSV (by saving them to CSV format; Excel can do that for you) and then use string-distance algorithm to locate differences. Files Comparer and other content-comparison tools use this algorithm to give pretty good results.

This approach has the added benefit (compared to linear cell-by-cell comparison) that any missing rows will be identified neatly, instead of marking rest of the entire data as different.