limits and offsets need to be externalized too. first draft

10 files changed, 22 insertions, 17 deletions

diff --git a/lib/arel/predicates.rb b/lib/arel/predicates.rb
index f21376d4c9..a83bad3c22 100644
--- a/lib/arel/predicates.rb
+++ b/lib/arel/predicates.rb
@@ -3,11 +3,8 @@ module Arel
   end
 
   class Binary < Predicate
-    attr_reader :operand1, :operand2
-
-    def initialize(operand1, operand2)
-      @operand1, @operand2 = operand1, operand2
-    end
+    attributes :operand1, :operand2
+    deriving :initialize
 
     def ==(other)
       self.class === other          and
diff --git a/lib/arel/relations/operations/group.rb b/lib/arel/relations/operations/group.rb
index 22af2734a6..253c4215b6 100644
--- a/lib/arel/relations/operations/group.rb
+++ b/lib/arel/relations/operations/group.rb
@@ -8,7 +8,7 @@ module Arel
       @groupings = (groupings + (block_given?? [yield(self)] : [])).collect { |g| g.bind(relation) }
     end
 
-    def aggregation?
+    def externalizable?
       true
     end
   end
diff --git a/lib/arel/relations/operations/join.rb b/lib/arel/relations/operations/join.rb
index 243a0289c7..8025db095e 100644
--- a/lib/arel/relations/operations/join.rb
+++ b/lib/arel/relations/operations/join.rb
@@ -39,8 +39,8 @@ module Arel
     end
     
     # TESTME
-    def aggregation?
-      relation1.aggregation? or relation2.aggregation?
+    def externalizable?
+      relation1.externalizable? or relation2.externalizable?
     end
     
     def join?
diff --git a/lib/arel/relations/operations/project.rb b/lib/arel/relations/operations/project.rb
index 2be87fe694..c92a9df5a5 100644
--- a/lib/arel/relations/operations/project.rb
+++ b/lib/arel/relations/operations/project.rb
@@ -12,8 +12,8 @@ module Arel
       @attributes ||= projections.collect { |p| p.bind(self) }
     end
     
-    def aggregation?
-      attributes.any?(&:aggregation?)
+    def externalizable?
+      attributes.any?(&:aggregation?) or relation.externalizable?
     end
   end
 end
\ No newline at end of file
diff --git a/lib/arel/relations/operations/skip.rb b/lib/arel/relations/operations/skip.rb
index ea5df21f53..930e4c94ea 100644
--- a/lib/arel/relations/operations/skip.rb
+++ b/lib/arel/relations/operations/skip.rb
@@ -2,5 +2,9 @@ module Arel
   class Skip < Compound
     attributes :relation, :skipped
     deriving :initialize, :==
+    
+    def externalizable?
+      true
+    end
   end
 end
\ No newline at end of file
diff --git a/lib/arel/relations/operations/take.rb b/lib/arel/relations/operations/take.rb
index 095e430417..2fd3fdf635 100644
--- a/lib/arel/relations/operations/take.rb
+++ b/lib/arel/relations/operations/take.rb
@@ -2,5 +2,9 @@ module Arel
   class Take < Compound
     attributes :relation, :taken
     deriving :initialize, :==
+    
+    def externalizable?
+      true
+    end
   end
 end
\ No newline at end of file
diff --git a/lib/arel/relations/utilities/aggregation.rb b/lib/arel/relations/utilities/aggregation.rb
index 9f5ead8f86..bdc7650a20 100644
--- a/lib/arel/relations/utilities/aggregation.rb
+++ b/lib/arel/relations/utilities/aggregation.rb
@@ -1,5 +1,5 @@
 module Arel
-  class Aggregation < Compound
+  class Externalization < Compound
     attributes :relation
     deriving :initialize, :==
     include Recursion::BaseCase
@@ -17,16 +17,16 @@ module Arel
     end
     
     def name
-      relation.name + '_aggregation'
+      relation.name + '_external'
     end
   end
   
   class Relation
     def externalize
-      @externalized ||= aggregation?? Aggregation.new(self) : self
+      @externalized ||= externalizable?? Externalization.new(self) : self
     end
     
-    def aggregation?
+    def externalizable?
       false
     end
   end
diff --git a/lib/arel/relations/utilities/compound.rb b/lib/arel/relations/utilities/compound.rb
index 23a55d4b5b..a91cec1127 100644
--- a/lib/arel/relations/utilities/compound.rb
+++ b/lib/arel/relations/utilities/compound.rb
@@ -2,7 +2,7 @@ module Arel
   class Compound < Relation
     attr_reader :relation
     hash_on :relation
-    delegate :joins, :join?, :inserts, :taken, :skipped, :name, :aggregation?,
+    delegate :joins, :join?, :inserts, :taken, :skipped, :name, :externalizable?,
              :column_for, :engine, :table, :table_sql,
              :to => :relation
     
diff --git a/lib/arel/relations/writes/delete.rb b/lib/arel/relations/writes/delete.rb
index e72679c4d6..318a299b8b 100644
--- a/lib/arel/relations/writes/delete.rb
+++ b/lib/arel/relations/writes/delete.rb
@@ -8,7 +8,7 @@ module Arel
         "DELETE",
         "FROM #{table_sql}",
         ("WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}" unless wheres.blank?  ),
-        ("LIMIT     #{taken}"                                  unless taken.blank?    ),
+        ("LIMIT #{taken}"                                     unless taken.blank?    ),
       ].compact.join("\n")
     end
     
diff --git a/lib/arel/relations/writes/update.rb b/lib/arel/relations/writes/update.rb
index 18b7ad9de1..720b9d697d 100644
--- a/lib/arel/relations/writes/update.rb
+++ b/lib/arel/relations/writes/update.rb
@@ -14,7 +14,7 @@ module Arel
           "#{value.format(attribute)} = #{attribute.format(value)}"
         end.join(",\n"),
         ("WHERE #{wheres.collect(&:to_sql).join('\n\tAND ')}"  unless wheres.blank?  ),
-        ("LIMIT     #{taken}"                                  unless taken.blank?    )
+        ("LIMIT #{taken}"                                      unless taken.blank?    )
       ].join("\n")
     end