Way to rollback or revert SVN repository

Sometimes we want to revert a svn repository because of bad commits.

Here is a quote from: http://stackoverflow.com/questions/2324999/revert-a-svn-folder-to-a-previous-revision

Assuming you want to revert from current HEAD (last commited) version to revision 268:

cd folder svn up svn merge -r HEAD:268 . 

Then resolve any conflicts manually (there should be nothing if there is no local change) and:

svn commit "- reverted to revision 268" 

To revert single change (e.g. made in revision 666):

cd folder svn merge -c -666 . 

To revert local changes (not committed yet):

cd folder svn revert -R .