scalars are now lifted; the heavy lifting is done by the operations on relation (select, join, etc.)

21 files changed, 100 insertions, 75 deletions

diff --git a/lib/active_relation/extensions/array.rb b/lib/active_relation/extensions/array.rb
index 5b6d6d6abd..aa4354a78a 100644
--- a/lib/active_relation/extensions/array.rb
+++ b/lib/active_relation/extensions/array.rb
@@ -2,4 +2,8 @@ class Array
   def to_hash
     Hash[*flatten]
   end
+
+  def to_sql(strategy = nil)
+    "(#{collect(&:to_sql).join(', ')})"
+  end
 end
\ No newline at end of file
diff --git a/lib/active_relation/extensions/class.rb b/lib/active_relation/extensions/class.rb
deleted file mode 100644
index 72b3bf0c15..0000000000
--- a/lib/active_relation/extensions/class.rb
+++ /dev/null
@@ -1,7 +0,0 @@
-class Class
-  def memoize(method)
-    define_method "#{method}_with_memoization" do |*args|
-    end
-    alias_method_chain method, :memoization
-  end
-end
\ No newline at end of file
diff --git a/lib/active_relation/extensions/hash.rb b/lib/active_relation/extensions/hash.rb
index 50864912bf..a33ace5738 100644
--- a/lib/active_relation/extensions/hash.rb
+++ b/lib/active_relation/extensions/hash.rb
@@ -1,11 +1,11 @@
 class Hash
-  def alias(&block)
-    inject({}) do |aliased, (key, value)|
-      aliased.merge(yield(key) => value)
-    end
+  def bind(relation)
+    descend { |x| x.bind(relation) }
   end
   
-  def to_sql(strategy = nil)
-    "(#{values.collect(&:to_sql).join(', ')})"
+  def descend(&block)
+    inject({}) do |descendent, (key, value)|
+      descendent.merge(yield(key) => yield(value))
+    end
   end
 end
\ No newline at end of file
diff --git a/lib/active_relation/extensions/object.rb b/lib/active_relation/extensions/object.rb
index b0c7ada999..d13cf9aabb 100644
--- a/lib/active_relation/extensions/object.rb
+++ b/lib/active_relation/extensions/object.rb
@@ -1,18 +1,6 @@
-class Object
-  def qualify
-    self
-  end
-  
+class Object  
   def bind(relation)
-    self
-  end
-  
-  def to_sql(strategy = self.strategy)
-    strategy.scalar self
-  end
-  
-  def strategy
-    ActiveRelation::Sql::Scalar.new(ActiveRelation::Table.engine)
+    ActiveRelation::Scalar.new(self, relation)
   end
   
   def metaclass
diff --git a/lib/active_relation/predicates.rb b/lib/active_relation/predicates.rb
index ddc6eab02b..ba926a86e5 100644
--- a/lib/active_relation/predicates.rb
+++ b/lib/active_relation/predicates.rb
@@ -84,7 +84,7 @@ module ActiveRelation
 
   class RelationInclusion < Binary
     alias_method :relation, :operand2
-    
+
     protected
     def predicate_sql
       'IN'
diff --git a/lib/active_relation/primitives.rb b/lib/active_relation/primitives.rb
index 2ac157297e..7629256034 100644
--- a/lib/active_relation/primitives.rb
+++ b/lib/active_relation/primitives.rb
@@ -1,3 +1,4 @@
 require 'active_relation/primitives/attribute'
+require 'active_relation/primitives/scalar'
 require 'active_relation/primitives/expression'
 
diff --git a/lib/active_relation/primitives/scalar.rb b/lib/active_relation/primitives/scalar.rb
new file mode 100644
index 0000000000..fa88404ee3
--- /dev/null
+++ b/lib/active_relation/primitives/scalar.rb
@@ -0,0 +1,25 @@
+module ActiveRelation
+  class Scalar
+    attr_reader :value, :relation
+    
+    def initialize(value, relation)
+      @value, @relation = value, relation
+    end
+    
+    def to_sql(strategy = self.strategy)
+      strategy.scalar value
+    end
+
+    def strategy
+      ActiveRelation::Sql::Scalar.new(relation.engine)
+    end
+    
+    def ==(other)
+      value == other.value
+    end
+    
+    def qualify
+      self
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/active_relation/relations/insertion.rb b/lib/active_relation/relations/insertion.rb
index dd5b8ec530..16fe3d5f46 100644
--- a/lib/active_relation/relations/insertion.rb
+++ b/lib/active_relation/relations/insertion.rb
@@ -11,7 +11,7 @@ module ActiveRelation
         "INSERT",
         "INTO #{table_sql}",
         "(#{record.keys.collect(&:to_sql).join(', ')})",
-        "VALUES #{record.to_sql}"
+        "VALUES #{record.values.to_sql}"
       ].join("\n")
     end
     
diff --git a/lib/active_relation/relations/order.rb b/lib/active_relation/relations/order.rb
index e6395aecd7..6949b3acf7 100644
--- a/lib/active_relation/relations/order.rb
+++ b/lib/active_relation/relations/order.rb
@@ -7,8 +7,9 @@ module ActiveRelation
     end
 
     def ==(other)
-      relation == other.relation and
-      orders   == other.orders
+      self.class  == other.class    and
+      relation    == other.relation and
+      orders      == other.orders
     end
 
     def descend(&block)
diff --git a/lib/active_relation/relations/relation.rb b/lib/active_relation/relations/relation.rb
index 3d4ff6613c..1c97cc7035 100644
--- a/lib/active_relation/relations/relation.rb
+++ b/lib/active_relation/relations/relation.rb
@@ -42,11 +42,11 @@ module ActiveRelation
       end
 
       def select(*predicates)
-        Selection.new(self, *predicates)
+        Selection.new(self, *predicates.collect {|p| p.bind(self)})
       end
 
       def project(*attributes)
-        Projection.new(self, *attributes)
+        Projection.new(self, *attributes.collect {|a| a.bind(self)})
       end
       
       def as(aliaz)
@@ -54,7 +54,7 @@ module ActiveRelation
       end
 
       def order(*attributes)
-        Order.new(self, *attributes)
+        Order.new(self, *attributes.collect {|a| a.bind(self)})
       end
   
       def rename(attribute, aliaz)
@@ -67,11 +67,11 @@ module ActiveRelation
       
       module Writes
         def insert(record)
-          session.create Insertion.new(self, record); self
+          session.create Insertion.new(self, record.bind(self)); self
         end
 
         def update(assignments)
-          session.update Update.new(self, assignments); self
+          session.update Update.new(self, assignments.bind(self)); self
         end
 
         def delete
@@ -108,14 +108,14 @@ module ActiveRelation
 
     def to_sql(strategy = Sql::Relation.new(engine))
       strategy.select [
-        "SELECT #{attributes.collect{ |a| a.to_sql(Sql::Projection.new(engine)) }.join(', ')}",
-        "FROM #{table_sql}",
-        (joins unless joins.blank?),
-        ("WHERE #{selects.collect{|s| s.to_sql(Sql::Selection.new(engine))}.join("\n\tAND ")}" unless selects.blank?),
-        ("ORDER BY #{orders.collect(&:to_sql)}" unless orders.blank?),
-        ("GROUP BY #{groupings.collect(&:to_sql)}" unless groupings.blank?),
-        ("LIMIT #{limit.to_sql}" unless limit.blank?),
-        ("OFFSET #{offset.to_sql}" unless offset.blank?)
+        "SELECT     #{attributes.collect{ |a| a.to_sql(Sql::Projection.new(engine)) }.join(', ')}",
+        "FROM       #{table_sql}",
+        (joins                                                                                      unless joins.blank?     ),
+        ("WHERE     #{selects.collect{|s| s.to_sql(Sql::Selection.new(engine))}.join("\n\tAND ")}"  unless selects.blank?   ),
+        ("ORDER BY  #{orders.collect(&:to_sql)}"                                                    unless orders.blank?    ),
+        ("GROUP BY  #{groupings.collect(&:to_sql)}"                                                 unless groupings.blank? ),
+        ("LIMIT     #{limit}"                                                                       unless limit.blank?     ),
+        ("OFFSET    #{offset}"                                                                      unless offset.blank?    )
       ].compact.join("\n"), self.alias
     end
     alias_method :to_s, :to_sql
@@ -127,6 +127,14 @@ module ActiveRelation
     def attribute_for_attribute(attribute)
       attributes.detect { |a| a =~ attribute }
     end
+    
+    def bind(relation)
+      self
+    end
+    
+    def strategy
+      Sql::Predicate.new(engine)
+    end
 
     def attributes;  []  end
     def selects;     []  end
diff --git a/lib/active_relation/relations/rename.rb b/lib/active_relation/relations/rename.rb
index 9a0e5552c7..ac5484bfff 100644
--- a/lib/active_relation/relations/rename.rb
+++ b/lib/active_relation/relations/rename.rb
@@ -15,7 +15,7 @@ module ActiveRelation
     end
     
     def attributes
-      relation.attributes.collect(&method(:baptize))
+      relation.attributes.collect(&method(:christen))
     end
     
     def descend(&block)
@@ -23,7 +23,7 @@ module ActiveRelation
     end
     
     private
-    def baptize(attribute)
+    def christen(attribute)
       (attribute =~ self.attribute ? attribute.as(pseudonym) : attribute).bind(self) rescue nil
     end
   end
diff --git a/lib/active_relation/relations/update.rb b/lib/active_relation/relations/update.rb
index 8909ee80a0..c50919af3e 100644
--- a/lib/active_relation/relations/update.rb
+++ b/lib/active_relation/relations/update.rb
@@ -9,7 +9,9 @@ module ActiveRelation
     def to_sql(strategy = nil)
       [
         "UPDATE #{table_sql} SET",
-        assignments.inject([]) { |assignments, (attribute, value)| assignments << "#{attribute.to_sql} = #{value.to_sql}" }.join(" "),
+        assignments.inject("") do |assignments, (attribute, value)| 
+          assignments << " #{attribute.to_sql} = #{value.to_sql}"
+        end,
         ("WHERE #{selects.collect(&:to_sql).join('\n\tAND ')}" unless selects.blank?)
       ].join("\n")
     end
diff --git a/lib/active_relation/sql.rb b/lib/active_relation/sql.rb
index a5701ca8cd..99cfc66383 100644
--- a/lib/active_relation/sql.rb
+++ b/lib/active_relation/sql.rb
@@ -20,7 +20,7 @@ module ActiveRelation
       end
       
       def select(select_sql, aliaz)
-        "(#{select_sql})" + (aliaz ? " AS #{quote_column_name(aliaz)}" : "")
+        "(#{select_sql})" + (aliaz ? " AS #{quote(aliaz)}" : "")
       end
     end
     
diff --git a/spec/active_relation/unit/predicates/binary_spec.rb b/spec/active_relation/unit/predicates/binary_spec.rb
index f6466d9105..677d8f3ab4 100644
--- a/spec/active_relation/unit/predicates/binary_spec.rb
+++ b/spec/active_relation/unit/predicates/binary_spec.rb
@@ -55,7 +55,7 @@ module ActiveRelation
       end
       
       it 'appropriately quotes scalars' do
-        ConcreteBinary.new(@attribute1, "1-asdf").to_sql.should be_like("
+        ConcreteBinary.new(@attribute1, "1-asdf".bind(@relation1)).to_sql.should be_like("
           `users`.`id` <=> 1
         ")        
       end
diff --git a/spec/active_relation/unit/predicates/relation_inclusion_spec.rb b/spec/active_relation/unit/predicates/relation_inclusion_spec.rb
index 0ac7ccb6e2..af5846b747 100644
--- a/spec/active_relation/unit/predicates/relation_inclusion_spec.rb
+++ b/spec/active_relation/unit/predicates/relation_inclusion_spec.rb
@@ -3,23 +3,16 @@ require File.join(File.dirname(__FILE__), '..', '..', '..', 'spec_helper')
 module ActiveRelation
   describe RelationInclusion do
     before do
-      foo = Table.new(:foo)
-      @relation1 = foo.project(foo[:id])
-      @relation2 = Table.new(:bar)
-      @attribute = @relation1[:id]
-    end
-  
-    describe RelationInclusion, '==' do    
-      it "obtains if attribute1 and attribute2 are identical" do
-        RelationInclusion.new(@attribute, @relation1).should == RelationInclusion.new(@attribute, @relation1)
-        RelationInclusion.new(@attribute, @relation1).should_not == RelationInclusion.new(@attribute, @relation2)
-      end
+      users = Table.new(:users)
+      @relation = users.project(users[:id])
+      @attribute = @relation[:id]
     end
   
     describe RelationInclusion, '#to_sql' do
       it "manufactures subselect sql" do
-        RelationInclusion.new(@attribute, @relation1).to_sql.should be_like("
-          `foo`.`id` IN (SELECT `foo`.`id` FROM `foo`)
+        # remove when sufficient coverage of sql strategies exists
+        RelationInclusion.new(@attribute, @relation).to_sql.should be_like("
+          `users`.`id` IN (SELECT `users`.`id` FROM `users`)
         ")
       end
     end
diff --git a/spec/active_relation/unit/relations/insertion_spec.rb b/spec/active_relation/unit/relations/insertion_spec.rb
index b2b239097a..91bf7773c1 100644
--- a/spec/active_relation/unit/relations/insertion_spec.rb
+++ b/spec/active_relation/unit/relations/insertion_spec.rb
@@ -8,7 +8,7 @@ module ActiveRelation
   
     describe '#to_sql' do
       it 'manufactures sql inserting the data for one item' do
-        Insertion.new(@relation, @relation[:name] => "nick").to_sql.should be_like("
+        Insertion.new(@relation, @relation[:name] => "nick".bind(@relation)).to_sql.should be_like("
           INSERT
           INTO `users`
           (`users`.`name`) VALUES ('nick')
diff --git a/spec/active_relation/unit/relations/join_spec.rb b/spec/active_relation/unit/relations/join_spec.rb
index 64d41effc5..a424239c4b 100644
--- a/spec/active_relation/unit/relations/join_spec.rb
+++ b/spec/active_relation/unit/relations/join_spec.rb
@@ -81,7 +81,7 @@ module ActiveRelation
           .aggregate(@relation2[:user_id], @relation2[:id].count) \
           .group(@relation2[:user_id]) \
           .rename(@relation2[:id].count, :cnt) \
-          .as(:photo_count)
+          .as('photo_count')
       end
       
       describe '#attributes' do
diff --git a/spec/active_relation/unit/relations/relation_spec.rb b/spec/active_relation/unit/relations/relation_spec.rb
index 3af3b8aa9c..8f35760801 100644
--- a/spec/active_relation/unit/relations/relation_spec.rb
+++ b/spec/active_relation/unit/relations/relation_spec.rb
@@ -89,7 +89,7 @@ module ActiveRelation
         end
     
         it "accepts arbitrary strings" do
-          @relation.select("arbitrary").should == Selection.new(@relation, "arbitrary")
+          @relation.select("arbitrary").should == Selection.new(@relation, Scalar.new("arbitrary", @relation))
         end
       end
   
@@ -100,9 +100,17 @@ module ActiveRelation
       end
       
       describe '#aggregate' do
+        before do
+          @expression1 = @attribute1.sum
+          @expression2 = @attribute2.sum
+        end
+        
         it 'manufactures a group relation' do
           @relation.aggregate(@expression1, @expression2).group(@attribute1, @attribute2). \
-            should == Aggregation.new(@relation, :expressions => [@expresion, @expression2], :groupings => [@attribute1, @attribute2])
+            should == Aggregation.new(@relation,
+                        :expressions => [@expression1, @expression2],
+                        :groupings => [@attribute1, @attribute2]
+                      )
         end
       end
       
@@ -119,7 +127,8 @@ module ActiveRelation
         describe '#insert' do
           it 'manufactures an insertion relation' do
             Session.start do
-              mock(Session.new).create(Insertion.new(@relation, record = {@relation[:name] => 'carl'}))
+              record = {@relation[:name] => 'carl'}
+              mock(Session.new).create(Insertion.new(@relation, record.bind(@relation)))
               @relation.insert(record).should == @relation
             end
           end
@@ -128,7 +137,8 @@ module ActiveRelation
         describe '#update' do
           it 'manufactures an update relation' do
             Session.start do
-              mock(Session.new).update(Update.new(@relation, assignments = {@relation[:name] => 'bob'}))
+              assignments = {@relation[:name] => Scalar.new('bob', @relation)}
+              mock(Session.new).update(Update.new(@relation, assignments.bind(@relation)))
               @relation.update(assignments).should == @relation
             end
           end
diff --git a/spec/active_relation/unit/relations/selection_spec.rb b/spec/active_relation/unit/relations/selection_spec.rb
index 3a18d4ae6e..d5e0c6a9f6 100644
--- a/spec/active_relation/unit/relations/selection_spec.rb
+++ b/spec/active_relation/unit/relations/selection_spec.rb
@@ -4,12 +4,12 @@ module ActiveRelation
   describe Selection do
     before do
       @relation = Table.new(:users)
-      @predicate = Equality.new(@relation[:id], 1)
+      @predicate = Equality.new(@relation[:id], 1.bind(@relation))
     end
   
     describe '#initialize' do
       it "manufactures nested selection relations if multiple predicates are provided" do
-        @predicate2 = LessThan.new(@relation[:age], 2)
+        @predicate2 = LessThan.new(@relation[:age], 2.bind(@relation))
         Selection.new(@relation, @predicate, @predicate2). \
           should == Selection.new(Selection.new(@relation, @predicate2), @predicate)
       end
@@ -39,7 +39,7 @@ module ActiveRelation
       end
     
       it "allows arbitrary sql" do
-        Selection.new(@relation, "asdf").to_sql.should be_like("
+        Selection.new(@relation, "asdf".bind(@relation)).to_sql.should be_like("
           SELECT `users`.`id`, `users`.`name`
           FROM `users`
           WHERE asdf
diff --git a/spec/active_relation/unit/relations/update_spec.rb b/spec/active_relation/unit/relations/update_spec.rb
index 2cd3eb9d11..cad14fd5ec 100644
--- a/spec/active_relation/unit/relations/update_spec.rb
+++ b/spec/active_relation/unit/relations/update_spec.rb
@@ -8,14 +8,14 @@ module ActiveRelation
   
     describe '#to_sql' do
       it 'manufactures sql updating attributes' do
-        Update.new(@relation, @relation[:name] => "nick").to_sql.should be_like("
+        Update.new(@relation, @relation[:name] => "nick".bind(@relation)).to_sql.should be_like("
           UPDATE `users`
           SET `users`.`name` = 'nick'
         ")
       end
       
       it 'manufactures sql updating a selection relation' do
-        Update.new(@relation.select(@relation[:id].equals(1)), @relation[:name] => "nick").to_sql.should be_like("
+        Update.new(@relation.select(@relation[:id].equals(1)), @relation[:name] => "nick".bind(@relation)).to_sql.should be_like("
           UPDATE `users`
           SET `users`.`name` = 'nick'
           WHERE `users`.`id` = 1
diff --git a/spec/active_relation/unit/session/session_spec.rb b/spec/active_relation/unit/session/session_spec.rb
index 1ac69976b5..89d96ef323 100644
--- a/spec/active_relation/unit/session/session_spec.rb
+++ b/spec/active_relation/unit/session/session_spec.rb
@@ -32,8 +32,8 @@ module ActiveRelation
     
     describe Session::CRUD do
       before do
-        @insert = Insertion.new(@relation, @relation[:name] => 'nick')
-        @update = Update.new(@relation, @relation[:name] => 'nick')
+        @insert = Insertion.new(@relation, @relation[:name] => 'nick'.bind(@relation))
+        @update = Update.new(@relation, @relation[:name] => 'nick'.bind(@relation))
         @delete = Deletion.new(@relation)
         @select = @relation
       end