Make Relation#destroy_all handle all the cases

activerecord/lib/active_record/base.rb

@@ -556,7 +556,7 @@ module ActiveRecord #:nodoc:
       end
       alias :colorize_logging= :colorize_logging
 
-      delegate :find, :first, :last, :all, :to => :scoped
+      delegate :find, :first, :last, :all, :destroy_all, :to => :scoped
       delegate :select, :group, :order, :limit, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :to => :scoped
       delegate :count, :average, :minimum, :maximum, :sum, :calculate, :to => :scoped
 
@@ -773,36 +773,6 @@ module ActiveRecord #:nodoc:
         relation.update(sanitize_sql_for_assignment(updates))
       end
 
-      # Destroys the records matching +conditions+ by instantiating each
-      # record and calling its +destroy+ method. Each object's callbacks are
-      # executed (including <tt>:dependent</tt> association options and
-      # +before_destroy+/+after_destroy+ Observer methods). Returns the
-      # collection of objects that were destroyed; each will be frozen, to
-      # reflect that no changes should be made (since they can't be
-      # persisted).
-      #
-      # Note: Instantiation, callback execution, and deletion of each
-      # record can be time consuming when you're removing many records at
-      # once. It generates at least one SQL +DELETE+ query per record (or
-      # possibly more, to enforce your callbacks). If you want to delete many
-      # rows quickly, without concern for their associations or callbacks, use
-      # +delete_all+ instead.
-      #
-      # ==== Parameters
-      #
-      # * +conditions+ - A string, array, or hash that specifies which records
-      #   to destroy. If omitted, all records are destroyed. See the
-      #   Conditions section in the introduction to ActiveRecord::Base for
-      #   more information.
-      #
-      # ==== Examples
-      #
-      #   Person.destroy_all("last_login < '2004-04-04'")
-      #   Person.destroy_all(:status => "inactive")
-      def destroy_all(conditions = nil)
-        where(conditions).destroy_all
-      end
-
       # Deletes the records matching +conditions+ without instantiating the records first, and hence not
       # calling the +destroy+ method nor invoking callbacks. This is a single SQL DELETE statement that
       # goes straight to the database, much more efficient than +destroy_all+. Be careful with relations

activerecord/lib/active_record/relation.rb

@@ -84,10 +84,40 @@ module ActiveRecord
       end
     end
 
-    def destroy_all
+    # Destroys the records matching +conditions+ by instantiating each
+    # record and calling its +destroy+ method. Each object's callbacks are
+    # executed (including <tt>:dependent</tt> association options and
+    # +before_destroy+/+after_destroy+ Observer methods). Returns the
+    # collection of objects that were destroyed; each will be frozen, to
+    # reflect that no changes should be made (since they can't be
+    # persisted).
+    #
+    # Note: Instantiation, callback execution, and deletion of each
+    # record can be time consuming when you're removing many records at
+    # once. It generates at least one SQL +DELETE+ query per record (or
+    # possibly more, to enforce your callbacks). If you want to delete many
+    # rows quickly, without concern for their associations or callbacks, use
+    # +delete_all+ instead.
+    #
+    # ==== Parameters
+    #
+    # * +conditions+ - A string, array, or hash that specifies which records
+    #   to destroy. If omitted, all records are destroyed. See the
+    #   Conditions section in the introduction to ActiveRecord::Base for
+    #   more information.
+    #
+    # ==== Examples
+    #
+    #   Person.destroy_all("last_login < '2004-04-04'")
+    #   Person.destroy_all(:status => "inactive")
+    def destroy_all(conditions = nil)
+      if conditions
+        where(conditions).destroy_all
+      else
         to_a.each {|object| object.destroy}
         reset
       end
+    end
 
     def delete_all
       arel.delete.tap { reset }