Add relation.from as a temporary workaround until arel relation has .from option

activerecord/lib/active_record/base.rb

@@ -1632,7 +1632,8 @@ def construct_finder_arel(options = {}, scope = scope(:find))
             group(construct_group(options[:group], options[:having], scope)).
             order(construct_order(options[:order], scope)).
             limit(construct_limit(options[:limit], scope)).
-            offset(construct_offset(options[:offset], scope))
+            offset(construct_offset(options[:offset], scope)).
+            from(options[:from])
 
           relation = relation.readonly if options[:readonly]
 

activerecord/lib/active_record/relation.rb

@@ -28,6 +28,14 @@ def select(selects)
       create_new_relation(@relation.project(selects))
     end
 
+    # TODO : This is temporary. We need .from in Arel.
+    attr_writer :from
+    def from(from)
+      relation = create_new_relation
+      relation.from = from
+      relation
+    end
+
     def group(groups)
       create_new_relation(@relation.group(groups))
     end
@@ -94,7 +102,7 @@ def to_a
             :conditions => where_clause,
             :limit => @relation.taken,
             :offset => @relation.skipped,
-            :from => @relation.send(:table_sql, Arel::Sql::TableReference.new(@relation))
+            :from => @from
             },
             ActiveRecord::Associations::ClassMethods::JoinDependency.new(@klass, @eager_load_associations, nil))
         end
@@ -242,8 +250,10 @@ def find_some(ids)
       end
     end
 
-    def create_new_relation(relation, readonly = @readonly, preload = @associations_to_preload, eager_load = @eager_load_associations)
-      Relation.new(@klass, relation, readonly, preload, eager_load)
+    def create_new_relation(relation = @relation, readonly = @readonly, preload = @associations_to_preload, eager_load = @eager_load_associations)
+      r = self.class.new(@klass, relation, readonly, preload, eager_load)
+      r.from = @from
+      r
     end
 
     def where_clause(join_string = "\n\tAND ")