An approach to awesome_nested_set issue 116

               indices[scope.call(root_node)] ||= 0
                set_left_and_rights.call(root_node)
              end
 +            
 +            # Set depths based on left/right nesting:
 +            if column_names.map(&:to_s).include?(depth_column_name.to_s)
 +              get_depths_sql = "SELECT #{quoted_table_name}.#{primary_key}, COUNT(parent.#{primary_key}) -1 AS #{quoted_depth_column_name}
 +              FROM #{quoted_table_name}, #{quoted_table_name} AS parent
 +              WHERE #{quoted_table_name}.#{quoted_left_column_name} BETWEEN parent.#{quoted_left_column_name} AND parent.#{quoted_right_column_name}"
 +              
 +              if acts_as_nested_set_options[:scope]
 +                scope_column_names.each do |scope_column|
 +                  get_depths_sql << " AND parent.#{connection.quote_column_name(scope_column)} = #{quoted_table_name}.#{connection.quote_column_name(scope_column)}"
 +                end
 +              end
 +              
 +              get_depths_sql << "
 +              GROUP BY #{quoted_table_name}.#{primary_key}
 +              ORDER BY #{quoted_table_name}.#{quoted_left_column_name}"
 +              
 +              connection.select_rows(get_depths_sql).each do |node_id, node_depth|
 +                  connection.update("UPDATE #{quoted_table_name} SET #{quoted_depth_column_name} = #{node_depth} WHERE #{primary_key} = #{node_id}")
 +              end
 +            end
 +            
            end
  
            # Iterates over tree elements and determines the current level in the tree.