4 files changed, 32 insertions, 0 deletions
diff --git a/lib/arel/attributes/attribute.rb b/lib/arel/attributes/attribute.rb
index af9bbdd478..bb85af4634 100644
--- a/lib/arel/attributes/attribute.rb
+++ b/lib/arel/attributes/attribute.rb
@@ -16,6 +16,10 @@ module Arel
       def sum
         Nodes::Sum.new [self], Nodes::SqlLiteral.new('sum_id')
       end
+
+      def maximum
+        Nodes::Max.new [self], Nodes::SqlLiteral.new('max_id')
+      end
     end
 
     class String  < Attribute; end
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index 24a71c54a2..28b9e61fb6 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -6,6 +6,7 @@ require 'arel/nodes/and'
 require 'arel/nodes/in'
 require 'arel/nodes/count'
 require 'arel/nodes/sum'
+require 'arel/nodes/max'
 require 'arel/nodes/sql_literal'
 require 'arel/nodes/select_core'
 require 'arel/nodes/select_statement'
diff --git a/lib/arel/nodes/max.rb b/lib/arel/nodes/max.rb
new file mode 100644
index 0000000000..1766c56058
--- /dev/null
+++ b/lib/arel/nodes/max.rb
@@ -0,0 +1,22 @@
+module Arel
+  module Nodes
+    class Max
+      attr_accessor :expressions, :alias
+
+      def initialize expr, aliaz = nil
+        @expressions = expr
+        @alias       = aliaz
+      end
+
+      def as aliaz
+        self.alias = SqlLiteral.new(aliaz)
+        self
+      end
+
+      def to_sql
+        viz = Visitors::ToSql.new Table.engine
+        viz.accept self
+      end
+    end
+  end
+end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 2a96444d59..e1cf0f3778 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -76,6 +76,11 @@ module Arel
           visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
       end
 
+      def visit_Arel_Nodes_Max o
+        "MAX(#{o.expressions.map { |x|
+          visit x }.join(', ')})#{o.alias ? " AS #{visit o.alias}" : ''}"
+      end
+
       def visit_Arel_Nodes_TableAlias o
         "#{visit o.relation} #{quote_table_name o.name}"
       end