Introduced concept of session. It does not yet support multiple databases, nor transactions, but it's a start!

7 files changed, 89 insertions, 27 deletions

diff --git a/lib/active_relation/relations.rb b/lib/active_relation/relations.rb
index 97c17b3792..f992fca8be 100644
--- a/lib/active_relation/relations.rb
+++ b/lib/active_relation/relations.rb
@@ -11,4 +11,5 @@ require 'active_relation/relations/rename'
 require 'active_relation/relations/deletion'
 require 'active_relation/relations/insertion'
 require 'active_relation/relations/update'
-require 'active_relation/relations/alias'
\ No newline at end of file
+require 'active_relation/relations/alias'
+require 'active_relation/sessions/session'
\ No newline at end of file
diff --git a/lib/active_relation/relations/deletion.rb b/lib/active_relation/relations/deletion.rb
index 4ac40a146b..f3d81baf27 100644
--- a/lib/active_relation/relations/deletion.rb
+++ b/lib/active_relation/relations/deletion.rb
@@ -10,6 +10,11 @@ module ActiveRelation
         "FROM #{table_sql}",
         ("WHERE #{selects.collect(&:to_sql).join('\n\tAND ')}" unless selects.blank?)
       ].compact.join("\n")
-    end  
+    end
+    
+    def ==(other)
+      self.class  == other.class    and
+      relation    == other.relation
+    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 31e4339ee0..dd5b8ec530 100644
--- a/lib/active_relation/relations/insertion.rb
+++ b/lib/active_relation/relations/insertion.rb
@@ -11,13 +11,14 @@ module ActiveRelation
         "INSERT",
         "INTO #{table_sql}",
         "(#{record.keys.collect(&:to_sql).join(', ')})",
-        "VALUES #{inserts.collect(&:to_sql).join(', ')}"
+        "VALUES #{record.to_sql}"
       ].join("\n")
-    end  
-
-    protected
-    def inserts
-      relation.inserts + [record]
+    end
+    
+    def ==(other)
+      self.class  == other.class    and
+      relation    == other.relation and
+      record      == other.record
     end
   end
 end
\ No newline at end of file
diff --git a/lib/active_relation/relations/relation.rb b/lib/active_relation/relations/relation.rb
index f20561c5b2..1d5e194923 100644
--- a/lib/active_relation/relations/relation.rb
+++ b/lib/active_relation/relations/relation.rb
@@ -2,18 +2,22 @@ module ActiveRelation
   class Relation
     include Sql::Quoting
 
-    module Iteration
-      include Enumerable
-  
+    def session
+      Session.instance
+    end
+
+    module Enumerable
+      include ::Enumerable
+
       def each(&block)
-        connection.select_all(to_s).each(&block)
+        session.read(self).each(&block)
       end
-  
+
       def first
-        connection.select_one(to_s)
+        session.read(self).first
       end
     end
-    include Iteration
+    include Enumerable
 
     module Operations
       def join(other)
@@ -58,18 +62,25 @@ module ActiveRelation
       def rename(attribute, aliaz)
         Rename.new(self, attribute => aliaz)
       end
-  
-      def insert(record)
-        Insertion.new(self, record)
-      end
-  
-      def delete
-        Deletion.new(self)
-      end
-      
+        
       def aggregate(*expressions)
         AggregateOperation.new(self, expressions)
       end
+      
+      module Writes
+        def insert(record)
+          session.create Insertion.new(self, record); self
+        end
+
+        def update(assignments)
+          session.update Update.new(self, assignments); self
+        end
+
+        def delete
+          session.delete Deletion.new(self); self
+        end
+      end
+      include Writes
   
       JoinOperation = Struct.new(:join_sql, :relation1, :relation2) do
         def on(*predicates)
@@ -84,7 +95,7 @@ module ActiveRelation
       end
     end
     include Operations
-
+    
     def aggregation?
       false
     end
diff --git a/lib/active_relation/relations/update.rb b/lib/active_relation/relations/update.rb
index d28608fdd5..8909ee80a0 100644
--- a/lib/active_relation/relations/update.rb
+++ b/lib/active_relation/relations/update.rb
@@ -12,6 +12,12 @@ module ActiveRelation
         assignments.inject([]) { |assignments, (attribute, value)| assignments << "#{attribute.to_sql} = #{value.to_sql}" }.join(" "),
         ("WHERE #{selects.collect(&:to_sql).join('\n\tAND ')}" unless selects.blank?)
       ].join("\n")
-    end  
+    end
+    
+    def ==(other)
+      self.class  == other.class    and
+      relation    == other.relation and
+      assignments == other.assignments
+    end
   end
 end
\ No newline at end of file
diff --git a/lib/active_relation/sessions/session.rb b/lib/active_relation/sessions/session.rb
new file mode 100644
index 0000000000..d6e2ae7169
--- /dev/null
+++ b/lib/active_relation/sessions/session.rb
@@ -0,0 +1,38 @@
+require 'singleton'
+
+module ActiveRelation
+  class Session
+    include Singleton
+        
+    module CRUD
+      def connection
+        ActiveRecord::Base.connection
+      end
+      
+      def create(insert)
+        connection.insert(insert.to_sql)
+      end
+      
+      def read(select)
+        connection.select_all(select.to_sql)
+      end
+      
+      def update(update)
+        connection.update(update.to_sql)
+      end
+      
+      def delete(delete)
+        connection.delete(delete.to_sql)
+      end
+    end
+    include CRUD
+    
+    module Transactions
+    end
+    include Transactions
+    
+    module UnitOfWork
+    end
+    include UnitOfWork
+  end
+end
\ No newline at end of file
diff --git a/lib/active_relation/sql.rb b/lib/active_relation/sql.rb
index 0384de44ef..85bcb4107b 100644
--- a/lib/active_relation/sql.rb
+++ b/lib/active_relation/sql.rb
@@ -2,7 +2,7 @@ module ActiveRelation
   module Sql
     module Quoting
       def connection
-        ActiveRecord::Base.connection
+        Session.instance.connection
       end
   
       delegate :quote_table_name, :quote_column_name, :quote, :to => :connection