4 files changed, 23 insertions, 0 deletions
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index 47cbd64eb5..2affd01fa8 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -6,6 +6,7 @@ require 'arel/nodes/not_equal'
 require 'arel/nodes/assignment'
 require 'arel/nodes/or'
 require 'arel/nodes/and'
+require 'arel/nodes/not'
 require 'arel/nodes/greater_than'
 require 'arel/nodes/greater_than_or_equal'
 require 'arel/nodes/less_than'
diff --git a/lib/arel/nodes/node.rb b/lib/arel/nodes/node.rb
index 43bad19488..841b954db9 100644
--- a/lib/arel/nodes/node.rb
+++ b/lib/arel/nodes/node.rb
@@ -4,6 +4,13 @@ module Arel
     # Abstract base class for all AST nodes
     class Node
       ###
+      # Factory method to create a Nodes::Not node that has the recipient of
+      # the caller as a child.
+      def not
+        Nodes::Not.new self
+      end
+
+      ###
       # Factory method to create a Nodes::Grouping node that has an Nodes::Or
       # node as a child.
       def or right
diff --git a/lib/arel/nodes/not.rb b/lib/arel/nodes/not.rb
new file mode 100644
index 0000000000..d463ae9d08
--- /dev/null
+++ b/lib/arel/nodes/not.rb
@@ -0,0 +1,11 @@
+module Arel
+  module Nodes
+    class Not < Arel::Nodes::Node
+      attr_reader :expr
+
+      def initialize expr
+        @expr = expr
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 528c5f6ced..bbc1eb3105 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -191,6 +191,10 @@ module Arel
         "ON #{visit o.expr}"
       end
 
+      def visit_Arel_Nodes_Not o
+        "NOT #{visit o.expr}"
+      end
+
       def visit_Arel_Table o
         if o.table_alias
           "#{quote_table_name o.name} #{quote_table_name o.table_alias}"