select  ITEM, I_NAME,C_NAME,S_NAME from(
select * from 
(select item_code as ITEM, ITEM_NAME as I_NAME, 1 as merge_key
from ITEM
where STOCK_MANAGEMENT_TYPE = 1)
left outer  join
(select CL_NAME as C_NAME,1 as merge_key from COLOR_TBL)
using (merge_key)

left outer  join
(select SIZE_NAME as S_NAME,1 as merge_key from SIZE_TBL)
using (merge_key))

order by 1,2,3