Is there a way to change a SVN users username through the entire repository history?

Question

When my team first started out with SVN we all just used our first names when committing to the repository, however, now that our team has grown, we are running into issues

Answer 1

yes there is:

svn propset --revprop -r revision_number svn:author new_username

However, svn does not allow changing revision properties by default. You need to set up a pre-revprop-change hook script for that. On windows, it suffices to put a bat-file in the hooks folder of your repository that simply contains one line:

exit 0

If that is set up, you should be able to write a script for your needs.

EDIT: I didn't test this through, but I think this should do the trick in PowerShell:

([xml] ( svn log --xml )).log.logentry 
   | ? {$_.author -eq "Mike"} 
   | foreach {svn propset --revprop -r $_.revision svn:author msmith}