basic rename functionality

3 files changed, 9 insertions, 0 deletions

diff --git a/lib/sql_algebra.rb b/lib/sql_algebra.rb
index b3e3c8d176..61625ff270 100644
--- a/lib/sql_algebra.rb
+++ b/lib/sql_algebra.rb
@@ -17,6 +17,7 @@ require 'sql_algebra/relations/projection_relation'
 require 'sql_algebra/relations/selection_relation'
 require 'sql_algebra/relations/order_relation'
 require 'sql_algebra/relations/range_relation'
+require 'sql_algebra/relations/rename_relation'
 require 'sql_algebra/relations/join'
 
 require 'sql_algebra/predicates/predicate'
diff --git a/lib/sql_algebra/relations/attribute.rb b/lib/sql_algebra/relations/attribute.rb
index 85d40dfb12..89ac495245 100644
--- a/lib/sql_algebra/relations/attribute.rb
+++ b/lib/sql_algebra/relations/attribute.rb
@@ -5,6 +5,10 @@ class Attribute
     @relation, @attribute_name, @aliaz = relation, attribute_name, aliaz
   end
   
+  def aliazz(aliaz)
+    Attribute.new(relation, attribute_name, aliaz)
+  end
+  
   def eql?(other)
     relation == other.relation and attribute_name == other.attribute_name
   end
diff --git a/lib/sql_algebra/relations/relation.rb b/lib/sql_algebra/relations/relation.rb
index 8c21927d01..02723ae0cc 100644
--- a/lib/sql_algebra/relations/relation.rb
+++ b/lib/sql_algebra/relations/relation.rb
@@ -32,6 +32,10 @@ class Relation
     def order(*attributes)
       OrderRelation.new(self, *attributes)
     end
+    
+    def rename(attribute, aliaz)
+      RenameRelation.new(self, attribute, aliaz)
+    end
   end
   include Operations