How to restore my blog

Do you have a backup of your database or do you just have the files on your webserver?

I have copied the whole directory sewing (including subfolders wp-content, wp-admin, wp-includes)

If you did not have SQL backup or even XML export before the post deletion, hope that Google had cached your pages and you can copy from the cache.

where is the SQL (file name) ?
ist it the file with the extension .sql ?

yes