Hi @AlBar,
Are you looking to delete everything? Or all the data for nodes matching some query?
For the first, the way to remove the whole database is to stop dgraph, remove the p and w directories and then restart.
For the second, it’s on the way Support variables in mutation blocks. · Issue #919 · dgraph-io/dgraph · GitHub (until it’s part of the query, the process is: query first, then issue a delete mutation)
Michael