Merge pull request #163 from atombender/master

Support for PARTITION BY in window

5 files changed, 83 insertions, 7 deletions

diff --git a/lib/arel/nodes/window.rb b/lib/arel/nodes/window.rb
index 60259e8c05..fee8eeff7a 100644
--- a/lib/arel/nodes/window.rb
+++ b/lib/arel/nodes/window.rb
@@ -1,10 +1,12 @@
 module Arel
   module Nodes
     class Window < Arel::Nodes::Node
-      attr_accessor :orders, :framing
+      attr_accessor :orders, :framing, :partitions
 
       def initialize
         @orders = []
+        @partitions = []
+        @framing = nil
       end
 
       def order *expr
@@ -15,16 +17,32 @@ module Arel
         self
       end
 
+      def partition *expr
+        # FIXME: We SHOULD NOT be converting these to SqlLiteral automatically
+        @partitions.concat expr.map { |x|
+          String === x || Symbol === x ? Nodes::SqlLiteral.new(x.to_s) : x
+        }
+        self
+      end
+
       def frame(expr)
         @framing = expr
       end
 
       def rows(expr = nil)
-        frame(Rows.new(expr))
+        if @framing
+          Rows.new(expr)
+        else
+          frame(Rows.new(expr))
+        end
       end
 
       def range(expr = nil)
-        frame(Range.new(expr))
+        if @framing
+          Range.new(expr)
+        else
+          frame(Range.new(expr))
+        end
       end
 
       def initialize_copy other
@@ -39,7 +57,8 @@ module Arel
       def eql? other
         self.class == other.class &&
           self.orders == other.orders &&
-          self.framing == other.framing
+          self.framing == other.framing &&
+          self.partitions == other.partitions
       end
       alias :== :eql?
     end
diff --git a/lib/arel/visitors/dot.rb b/lib/arel/visitors/dot.rb
index d96cf7a6a0..f0cefeabd7 100644
--- a/lib/arel/visitors/dot.rb
+++ b/lib/arel/visitors/dot.rb
@@ -82,12 +82,14 @@ module Arel
       alias :visit_Arel_Nodes_Range             :unary
 
       def window o
+        visit_edge o, "partitions"
         visit_edge o, "orders"
         visit_edge o, "framing"
       end
       alias :visit_Arel_Nodes_Window            :window
 
       def named_window o
+        visit_edge o, "partitions"
         visit_edge o, "orders"
         visit_edge o, "framing"
         visit_edge o, "name"
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 7f74ebb402..8c63070084 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -336,12 +336,20 @@ module Arel
 
       def visit_Arel_Nodes_Window o, collector
         collector << "("
+
+        if o.partitions.any?
+          collector << "PARTITION BY "
+          collector = inject_join o.partitions, collector, ", "
+        end
+
         if o.orders.any?
+          collector << ' ' if o.partitions.any?
           collector << "ORDER BY "
           collector = inject_join o.orders, collector, ", "
         end
 
         if o.framing
+          collector << ' ' if o.partitions.any? or o.orders.any?
           collector = visit o.framing, collector
         end
 
diff --git a/test/nodes/test_window.rb b/test/nodes/test_window.rb
index f09d16e441..9ec42be59f 100644
--- a/test/nodes/test_window.rb
+++ b/test/nodes/test_window.rb
@@ -7,9 +7,11 @@ module Arel
         it 'is equal with equal ivars' do
           window1 = Window.new
           window1.orders = [1, 2]
+          window1.partitions = [1]
           window1.frame 3
           window2 = Window.new
           window2.orders = [1, 2]
+          window2.partitions = [1]
           window2.frame 3
           array = [window1, window2]
           assert_equal 1, array.uniq.size
@@ -18,9 +20,11 @@ module Arel
         it 'is not equal with different ivars' do
           window1 = Window.new
           window1.orders = [1, 2]
+          window1.partitions = [1]
           window1.frame 3
           window2 = Window.new
           window2.orders = [1, 2]
+          window1.partitions = [1]
           window2.frame 4
           array = [window1, window2]
           assert_equal 2, array.uniq.size
@@ -33,9 +37,11 @@ module Arel
         it 'is equal with equal ivars' do
           window1 = NamedWindow.new 'foo'
           window1.orders = [1, 2]
+          window1.partitions = [1]
           window1.frame 3
           window2 = NamedWindow.new 'foo'
           window2.orders = [1, 2]
+          window2.partitions = [1]
           window2.frame 3
           array = [window1, window2]
           assert_equal 1, array.uniq.size
@@ -44,9 +50,11 @@ module Arel
         it 'is not equal with different ivars' do
           window1 = NamedWindow.new 'foo'
           window1.orders = [1, 2]
+          window1.partitions = [1]
           window1.frame 3
           window2 = NamedWindow.new 'bar'
           window2.orders = [1, 2]
+          window2.partitions = [1]
           window2.frame 3
           array = [window1, window2]
           assert_equal 2, array.uniq.size
@@ -68,6 +76,4 @@ module Arel
       end
     end
   end
-end
-
-
+end
\ No newline at end of file
diff --git a/test/test_select_manager.rb b/test/test_select_manager.rb
index 4678901bb4..0b9756709d 100644
--- a/test/test_select_manager.rb
+++ b/test/test_select_manager.rb
@@ -716,6 +716,47 @@ module Arel
         }
       end
 
+      it 'takes an order with multiple columns' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.from table
+        manager.window('a_window').order(table['foo'].asc, table['bar'].desc)
+        manager.to_sql.must_be_like %{
+          SELECT FROM "users" WINDOW "a_window" AS (ORDER BY "users"."foo" ASC, "users"."bar" DESC)
+        }
+      end
+
+      it 'takes a partition' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.from table
+        manager.window('a_window').partition(table['bar'])
+        manager.to_sql.must_be_like %{
+          SELECT FROM "users" WINDOW "a_window" AS (PARTITION BY "users"."bar")
+        }
+      end
+
+      it 'takes a partition and an order' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.from table
+        manager.window('a_window').partition(table['foo']).order(table['foo'].asc)
+        manager.to_sql.must_be_like %{
+          SELECT FROM "users" WINDOW "a_window" AS (PARTITION BY "users"."foo"
+            ORDER BY "users"."foo" ASC)
+        }
+      end
+
+      it 'takes a partition with multiple columns' do
+        table   = Table.new :users
+        manager = Arel::SelectManager.new Table.engine
+        manager.from table
+        manager.window('a_window').partition(table['bar'], table['baz'])
+        manager.to_sql.must_be_like %{
+          SELECT FROM "users" WINDOW "a_window" AS (PARTITION BY "users"."bar", "users"."baz")
+        }
+      end
+
       it 'takes a rows frame, unbounded preceding' do
         table   = Table.new :users
         manager = Arel::SelectManager.new Table.engine