qualified naming

14 files changed, 113 insertions, 33 deletions

diff --git a/lib/sql_algebra.rb b/lib/sql_algebra.rb
index 61625ff270..475bb23138 100644
--- a/lib/sql_algebra.rb
+++ b/lib/sql_algebra.rb
@@ -33,6 +33,7 @@ require 'sql_algebra/predicates/match_predicate'
 
 require 'sql_algebra/extensions/range'
 require 'sql_algebra/extensions/object'
+require 'sql_algebra/extensions/array'
 
 require 'sql_algebra/sql_builder/sql_builder'
 require 'sql_algebra/sql_builder/select_builder'
diff --git a/lib/sql_algebra/extensions/array.rb b/lib/sql_algebra/extensions/array.rb
new file mode 100644
index 0000000000..5b6d6d6abd
--- /dev/null
+++ b/lib/sql_algebra/extensions/array.rb
@@ -0,0 +1,5 @@
+class Array
+  def to_hash
+    Hash[*flatten]
+  end
+end
\ No newline at end of file
diff --git a/lib/sql_algebra/extensions/base.rb b/lib/sql_algebra/extensions/base.rb
index 79f2ce75d1..0143caf23d 100644
--- a/lib/sql_algebra/extensions/base.rb
+++ b/lib/sql_algebra/extensions/base.rb
@@ -3,12 +3,12 @@ class ActiveRecord::Base
     object = cache.get(record % klass.primary_key) { Klass.instantiate(record % Klass.attributes) }
     includes.each do |include|
       case include
-        when Symbol
-          object.send(association = include).bring_forth(record)
-        when Hash
-          include.each do |association, nested_associations|
-            object.send(association).bring_forth(record, nested_associations)
-          end
+      when Symbol
+        object.send(association = include).bring_forth(record)
+      when Hash
+        include.each do |association, nested_associations|
+          object.send(association).bring_forth(record, nested_associations)
+        end
       end
     end
   end
diff --git a/lib/sql_algebra/extensions/object.rb b/lib/sql_algebra/extensions/object.rb
index 639e810a97..6ea66d7484 100644
--- a/lib/sql_algebra/extensions/object.rb
+++ b/lib/sql_algebra/extensions/object.rb
@@ -1,4 +1,8 @@
 class Object
+  def qualify
+    self
+  end
+  
   def to_sql(builder = EqualsConditionBuilder.new)
     me = self
     builder.call do
diff --git a/lib/sql_algebra/predicates/binary_predicate.rb b/lib/sql_algebra/predicates/binary_predicate.rb
index 9463f162c5..f5c420c833 100644
--- a/lib/sql_algebra/predicates/binary_predicate.rb
+++ b/lib/sql_algebra/predicates/binary_predicate.rb
@@ -10,6 +10,10 @@ class BinaryPredicate < Predicate
       (attribute1.eql?(other.attribute1) and attribute2.eql?(other.attribute2))
   end
   
+  def qualify
+    self.class.new(attribute1.qualify, attribute2.qualify)
+  end
+  
   def to_sql(builder = ConditionsBuilder.new)
     builder.call do
       send(predicate_name) do
diff --git a/lib/sql_algebra/predicates/equality_predicate.rb b/lib/sql_algebra/predicates/equality_predicate.rb
index 2061d0f644..7040c45f67 100644
--- a/lib/sql_algebra/predicates/equality_predicate.rb
+++ b/lib/sql_algebra/predicates/equality_predicate.rb
@@ -4,7 +4,7 @@ class EqualityPredicate < BinaryPredicate
       ((attribute1.eql?(other.attribute1) and attribute2.eql?(other.attribute2)) or
        (attribute1.eql?(other.attribute2) and attribute2.eql?(other.attribute1)))
   end
-  
+    
   protected
   def predicate_name
     :equals
diff --git a/lib/sql_algebra/relations/attribute.rb b/lib/sql_algebra/relations/attribute.rb
index 89ac495245..7583553b80 100644
--- a/lib/sql_algebra/relations/attribute.rb
+++ b/lib/sql_algebra/relations/attribute.rb
@@ -1,45 +1,56 @@
 class Attribute
-  attr_reader :relation, :attribute_name, :aliaz
+  attr_reader :relation, :name, :aliaz
   
-  def initialize(relation, attribute_name, aliaz = nil)
-    @relation, @attribute_name, @aliaz = relation, attribute_name, aliaz
+  def initialize(relation, name, aliaz = nil)
+    @relation, @name, @aliaz = relation, name, aliaz
   end
   
   def aliazz(aliaz)
-    Attribute.new(relation, attribute_name, aliaz)
+    Attribute.new(relation, name, aliaz)
   end
   
-  def eql?(other)
-    relation == other.relation and attribute_name == other.attribute_name
+  def qualified_name
+    "#{relation.table}.#{name}"
   end
   
-  def ==(other)
-    EqualityPredicate.new(self, other)
+  def qualify
+    aliazz(qualified_name)
   end
+
+  module Predications
+    def eql?(other)
+      relation == other.relation and name == other.name and aliaz == other.aliaz
+    end
   
-  def <(other)
-    LessThanPredicate.new(self, other)
-  end
+    def ==(other)
+      EqualityPredicate.new(self, other)
+    end
   
-  def <=(other)
-    LessThanOrEqualToPredicate.new(self, other)
-  end
+    def <(other)
+      LessThanPredicate.new(self, other)
+    end
   
-  def >(other)
-    GreaterThanPredicate.new(self, other)
-  end
+    def <=(other)
+      LessThanOrEqualToPredicate.new(self, other)
+    end
   
-  def >=(other)
-    GreaterThanOrEqualToPredicate.new(self, other)
-  end
+    def >(other)
+      GreaterThanPredicate.new(self, other)
+    end
   
-  def =~(regexp)
-    MatchPredicate.new(self, regexp)
+    def >=(other)
+      GreaterThanOrEqualToPredicate.new(self, other)
+    end
+  
+    def =~(regexp)
+      MatchPredicate.new(self, regexp)
+    end
   end
+  include Predications
   
   def to_sql(builder = SelectsBuilder.new)
     builder.call do
-      column relation.table, attribute_name, aliaz
+      column relation.table, name, aliaz
     end
   end
 end
\ No newline at end of file
diff --git a/lib/sql_algebra/relations/join_relation.rb b/lib/sql_algebra/relations/join_relation.rb
index dc57e24c96..c65b07225f 100644
--- a/lib/sql_algebra/relations/join_relation.rb
+++ b/lib/sql_algebra/relations/join_relation.rb
@@ -16,7 +16,7 @@ class JoinRelation < Relation
   end
   
   def selects
-    relation1.selects + relation2.selects
+    relation1.send(:selects) + relation2.send(:selects)
   end
   
   def attributes
diff --git a/lib/sql_algebra/relations/order_relation.rb b/lib/sql_algebra/relations/order_relation.rb
index 384a007bc2..b39dc45c3f 100644
--- a/lib/sql_algebra/relations/order_relation.rb
+++ b/lib/sql_algebra/relations/order_relation.rb
@@ -1,4 +1,4 @@
-class OrderRelation < Relation
+class OrderRelation < CompoundRelation
   attr_reader :relation, :attributes
   
   def initialize(relation, *attributes)
@@ -9,6 +9,10 @@ class OrderRelation < Relation
     relation == other.relation and attributes.eql?(other.attributes)
   end
   
+  def qualify
+    OrderRelation.new(relation.qualify, *attributes.collect { |a| a.qualify })
+  end
+  
   def to_sql(builder = SelectBuilder.new)
     relation.to_sql(builder).call do
       attributes.each do |attribute|
diff --git a/lib/sql_algebra/relations/projection_relation.rb b/lib/sql_algebra/relations/projection_relation.rb
index 0b5d645d79..1a0e8dbfe4 100644
--- a/lib/sql_algebra/relations/projection_relation.rb
+++ b/lib/sql_algebra/relations/projection_relation.rb
@@ -9,6 +9,10 @@ class ProjectionRelation < Relation
     relation == other.relation and attributes.eql?(other.attributes)
   end
   
+  def qualify
+    ProjectionRelation.new(relation.qualify, *attributes.collect(&:qualify))
+  end
+  
   def to_sql(builder = SelectBuilder.new)
     relation.to_sql(builder).call do
       select do
diff --git a/lib/sql_algebra/relations/relation.rb b/lib/sql_algebra/relations/relation.rb
index 02723ae0cc..82266fd7e8 100644
--- a/lib/sql_algebra/relations/relation.rb
+++ b/lib/sql_algebra/relations/relation.rb
@@ -34,7 +34,7 @@ class Relation
     end
     
     def rename(attribute, aliaz)
-      RenameRelation.new(self, attribute, aliaz)
+      RenameRelation.new(self, attribute => aliaz)
     end
   end
   include Operations
diff --git a/lib/sql_algebra/relations/rename_relation.rb b/lib/sql_algebra/relations/rename_relation.rb
new file mode 100644
index 0000000000..8acf5091b2
--- /dev/null
+++ b/lib/sql_algebra/relations/rename_relation.rb
@@ -0,0 +1,34 @@
+class RenameRelation < CompoundRelation
+  attr_reader :relation, :schmattribute, :aliaz
+  
+  def initialize(relation, renames)
+    @schmattribute, @aliaz = renames.shift
+    @relation = renames.empty?? relation : RenameRelation.new(relation, renames)
+  end
+  
+  def ==(other)
+    relation == other.relation and schmattribute.eql?(other.schmattribute) and aliaz == other.aliaz
+  end
+  
+  def attributes
+    relation.attributes.collect { |a| substitute(a) }
+  end
+  
+  def qualify
+    RenameRelation.new(relation.qualify, schmattribute.qualify => aliaz)
+  end
+  
+  protected
+  def attribute(name)
+    case
+    when name == aliaz then schmattribute.aliazz(aliaz)
+    when relation[name].eql?(schmattribute) then nil
+    else relation[name]
+    end
+  end
+  
+  private
+  def substitute(a)
+    a.eql?(schmattribute) ? a.aliazz(aliaz) : a
+  end
+end
\ No newline at end of file
diff --git a/lib/sql_algebra/relations/selection_relation.rb b/lib/sql_algebra/relations/selection_relation.rb
index 72911aa65a..dcf5f4745f 100644
--- a/lib/sql_algebra/relations/selection_relation.rb
+++ b/lib/sql_algebra/relations/selection_relation.rb
@@ -10,6 +10,11 @@ class SelectionRelation < CompoundRelation
     relation == other.relation and predicate == other.predicate
   end
   
+  def qualify
+    SelectionRelation.new(relation.qualify, predicate.qualify)
+  end
+  
+  protected
   def selects
     [predicate]
   end
diff --git a/lib/sql_algebra/relations/table_relation.rb b/lib/sql_algebra/relations/table_relation.rb
index 1915b42565..5a47ae7a34 100644
--- a/lib/sql_algebra/relations/table_relation.rb
+++ b/lib/sql_algebra/relations/table_relation.rb
@@ -8,6 +8,10 @@ class TableRelation < Relation
   def attributes
     attributes_by_name.values
   end
+  
+  def qualify
+    RenameRelation.new self, qualifications
+  end
     
   protected
   def attribute(name)
@@ -20,4 +24,8 @@ class TableRelation < Relation
       attributes_by_name.merge(column.name => Attribute.new(self, column.name.to_sym))
     end
   end
+  
+  def qualifications
+    attributes.zip(attributes.collect(&:qualified_name)).to_hash
+  end
 end
\ No newline at end of file