Our svn server has accidently lost its all data, and our svn repository files are lost. Currently we have only local checkouts of the svn repository, is there any way to rec
The whole svn history is in the server, so you cannot recover it from your checkouts. The only thing you can do is create a new repository and commit the code so you can start again.
In the future I would recommend you to keep a copy of you repository. Take a look to the svn dump command.
By any chance do you use TortoiseSVN as your SVN client?
TortoiseSVN caches log data from repositories it communicates with. Click Log Caching/Cached Repositories,
and from there you can "Export" cached log data in .CSV format.
Granted, this is not resurrecting a dead repository, (which is not possible using only a working copy) but perhaps some log data would be beneficial to you to see your former repository's change history.