code: def namedb_get_name_from_name_hash128( cur, name_hash128, block_number ):
      
  
      unexpired_query, unexpired_args = namedb_select_where_unexpired_names( block_number )
  
      select_query = "SELECT name FROM name_records JOIN namespaces ON name_records.namespace_id = namespaces.namespace_id " + \
                     "WHERE name_hash128 = ? AND revoked = 0 AND " + unexpired_query + ";"
  
      args = (name_hash128,) + unexpired_args
      name_rows = namedb_query_execute( cur, select_query, args )
  
      name_row = name_rows.fetchone()
      if name_row is None:
          # no such namespace 
          return None 
  
      return name_row['name']
docs: Given the hexlified 128-bit hash of a name, get the name.