group and having clause init

lib/smql_to_ar/query_builder.rb

@@ -43,6 +43,7 @@ class SmqlToAR
 			@table_alias[ @base_table] = @base_table.first
 			t = quote_table_name @table_alias[ @base_table]
 			@_select, @_joins, @_joined, @_includes, @_order = ["DISTINCT #{t}.*"], "", [@base_table], [], []
+			@_group, @_having = {}, {}
 			@table_model = {@base_table => @model}
 		end
 
@@ -66,6 +67,14 @@ class SmqlToAR
 			self
 		end
 
+		def group col
+			@_group.push col
+		end
+
+		def having h
+			@_having.update h
+		end
+
 		def quote_column_name name
 			@quoter.quote_column_name( name).gsub /"\."/, ','
 		end