Merge branch '2-0-stable' into merge

* 2-0-stable:
  updating history
  Patched Arel v2.0.6 to support MSSQL SQL queries. Based on work of James Abley (https://github.com/jabley/arel).
  consolidating dot visitor methods
  refactoring where, fixing subselect
  implementation for passing a subquery to #in and #not_in
  tests for passing a subquery to #in and #not_in
  limit members of the AST are visited
  quoting limit nodes

Conflicts:
	History.txt
	lib/arel/nodes.rb
	lib/arel/nodes/select_core.rb
	lib/arel/select_manager.rb
	lib/arel/visitors/to_sql.rb
	test/visitors/test_to_sql.rb

10 files changed, 60 insertions, 9 deletions

diff --git a/lib/arel/nodes/limit.rb b/lib/arel/nodes/limit.rb
new file mode 100644
index 0000000000..68ea95daf5
--- /dev/null
+++ b/lib/arel/nodes/limit.rb
@@ -0,0 +1,7 @@
+module Arel
+  module Nodes
+    class Limit < Arel::Nodes::Unary
+    end
+  end
+end
+
diff --git a/lib/arel/nodes/select_core.rb b/lib/arel/nodes/select_core.rb
index 8eb7c0d3e7..7f577e0a05 100644
--- a/lib/arel/nodes/select_core.rb
+++ b/lib/arel/nodes/select_core.rb
@@ -1,11 +1,12 @@
 module Arel
   module Nodes
     class SelectCore < Arel::Nodes::Node
-      attr_accessor :projections, :wheres, :groups
+      attr_accessor :top, :projections, :wheres, :groups
       attr_accessor :having, :source
 
       def initialize
         @source      = JoinSource.new nil
+        @top         = nil
         @projections = []
         @wheres      = []
         @groups      = []
diff --git a/lib/arel/nodes/top.rb b/lib/arel/nodes/top.rb
new file mode 100644
index 0000000000..56e2e97e8d
--- /dev/null
+++ b/lib/arel/nodes/top.rb
@@ -0,0 +1,6 @@
+module Arel
+  module Nodes
+    class Top < Arel::Nodes::Unary
+    end
+  end
+end
diff --git a/lib/arel/nodes/unary.rb b/lib/arel/nodes/unary.rb
index f679017597..e1576b9c99 100644
--- a/lib/arel/nodes/unary.rb
+++ b/lib/arel/nodes/unary.rb
@@ -10,12 +10,14 @@ module Arel
     end
 
     %w{
-      Not
       Group
       Grouping
-      Offset
       Having
+      Limit
+      Not
+      Offset
       On
+      Top
     }.each do |name|
       const_set(name, Class.new(Unary))
     end
diff --git a/lib/arel/select_manager.rb b/lib/arel/select_manager.rb
index 274633c9db..3e0d4038d7 100644
--- a/lib/arel/select_manager.rb
+++ b/lib/arel/select_manager.rb
@@ -10,7 +10,7 @@ module Arel
     end
 
     def limit
-      @ast.limit
+      @ast.limit && @ast.limit.expr
     end
     alias :taken :limit
 
@@ -137,7 +137,8 @@ module Arel
     end
 
     def take limit
-      @ast.limit = limit
+      @ast.limit = Nodes::Limit.new(limit)
+      @ctx.top   = Nodes::Top.new(limit)
       self
     end
 
diff --git a/lib/arel/visitors.rb b/lib/arel/visitors.rb
index 2b0a06d534..8410b2b912 100644
--- a/lib/arel/visitors.rb
+++ b/lib/arel/visitors.rb
@@ -4,6 +4,7 @@ require 'arel/visitors/to_sql'
 require 'arel/visitors/sqlite'
 require 'arel/visitors/postgresql'
 require 'arel/visitors/mysql'
+require 'arel/visitors/mssql'
 require 'arel/visitors/oracle'
 require 'arel/visitors/join_sql'
 require 'arel/visitors/where_sql'
@@ -16,6 +17,8 @@ module Arel
       'postgresql'      => Arel::Visitors::PostgreSQL,
       'mysql'           => Arel::Visitors::MySQL,
       'mysql2'          => Arel::Visitors::MySQL,
+      'mssql'           => Arel::Visitors::MSSQL,
+      'sqlserver'       => Arel::Visitors::MSSQL,
       'oracle_enhanced' => Arel::Visitors::Oracle,
       'sqlite'          => Arel::Visitors::SQLite,
       'sqlite3'         => Arel::Visitors::SQLite,
diff --git a/lib/arel/visitors/mssql.rb b/lib/arel/visitors/mssql.rb
new file mode 100644
index 0000000000..9b0e77c19b
--- /dev/null
+++ b/lib/arel/visitors/mssql.rb
@@ -0,0 +1,16 @@
+module Arel
+  module Visitors
+    class MSSQL < Arel::Visitors::ToSql
+      private
+
+      def visit_Arel_Nodes_Limit o
+        ""
+      end
+
+      def visit_Arel_Nodes_Top o
+        "TOP #{visit o.expr}"
+      end
+
+    end
+  end
+end
diff --git a/lib/arel/visitors/mysql.rb b/lib/arel/visitors/mysql.rb
index ace8fb0979..b37d76f710 100644
--- a/lib/arel/visitors/mysql.rb
+++ b/lib/arel/visitors/mysql.rb
@@ -10,7 +10,7 @@ module Arel
       # :'(
       # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214
       def visit_Arel_Nodes_SelectStatement o
-        o.limit = 18446744073709551615 if o.offset && !o.limit
+        o.limit = Arel::Nodes::Limit.new(18446744073709551615) if o.offset && !o.limit
         super
       end
 
diff --git a/lib/arel/visitors/sqlite.rb b/lib/arel/visitors/sqlite.rb
index c45160851d..237ae913bb 100644
--- a/lib/arel/visitors/sqlite.rb
+++ b/lib/arel/visitors/sqlite.rb
@@ -3,7 +3,7 @@ module Arel
     class SQLite < Arel::Visitors::ToSql
       private
       def visit_Arel_Nodes_SelectStatement o
-        o.limit = -1 if o.offset && !o.limit
+        o.limit = Arel::Nodes::Limit.new(-1) if o.offset && !o.limit
         super
       end
     end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index f25c0ee69f..9830e559d5 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -131,7 +131,7 @@ eowarn
         [
           o.cores.map { |x| visit_Arel_Nodes_SelectCore x }.join,
           ("ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty?),
-          ("LIMIT #{visit o.limit}" if o.limit),
+          (visit(o.limit) if o.limit),
           (visit(o.offset) if o.offset),
           (visit(o.lock) if o.lock),
         ].compact.join ' '
@@ -139,7 +139,9 @@ eowarn
 
       def visit_Arel_Nodes_SelectCore o
         [
-          "SELECT #{o.projections.map { |x| visit x }.join ', '}",
+          "SELECT",
+          (visit(o.top) if o.top),
+          "#{o.projections.map { |x| visit x }.join ', '}",
           visit(o.source),
           ("WHERE #{o.wheres.map { |x| visit x }.join ' AND ' }" unless o.wheres.empty?),
           ("GROUP BY #{o.groups.map { |x| visit x }.join ', ' }" unless o.groups.empty?),
@@ -155,6 +157,15 @@ eowarn
         "OFFSET #{visit o.expr}"
       end
 
+      def visit_Arel_Nodes_Limit o
+        "LIMIT #{visit o.expr}"
+      end
+
+      # FIXME: this does nothing on most databases, but does on MSSQL
+      def visit_Arel_Nodes_Top o
+        ""
+      end
+
       # FIXME: this does nothing on SQLLite3, but should do things on other
       # databases.
       def visit_Arel_Nodes_Lock o
@@ -357,6 +368,10 @@ eowarn
         o.empty? ? 'NULL' : o.map { |x| visit x }.join(', ')
       end
 
+      def visit_Array o
+        o.empty? ? 'NULL' : o.map { |x| visit x }.join(', ')
+      end
+
       def quote value, column = nil
         @connection.quote value, column
       end