sql - How to add letters to result data -

when run following query,

select  nvl(week, 'sum) week   , sum(a) a, sum(b) b   (   select b.*       table  b     b.week between '2013051' , '2013052'   )  group rollup(week) 

i data

   |  week  |       2013051      2013052 

but want data named below.

   |  week  |   2013. 05. 1 week   2013. 05. 2 week 

can me fixing this?

assuming week string:

select substr(week, 1, 4)     ||'. '|| substr(week, 5, 2)     ||'. '|| substr(week, 7, 1) ||' week' week, ... 

or if week can null (which can't data because of subquery's filter, generated null value rollup missed):

select case when week null 'sum'     else substr(week, 1, 4)         ||'. '|| substr(week, 5, 2)         ||'. '|| substr(week, 7, 1) ||' week' end week, ...  week                               b ---------------- ---------- ---------- 2013. 05. 1 week          1          2  2013. 05. 2 week          3          4  sum                       4          6  

sql fiddle demo; , 1 without subquery, seems superfluous here.