Select decode (to_char (sysdate, 'mm') - 1, 0, to_char (sysdate, 'yyyy') - 1, to_char (sysdate, 'yyyy')) || Case when to_number (decode (to_char (sysdate, 'mm ') -1 ,0, 12, to_char (sysdate,' mm ') - 1)) <10 TEN' 0 '|| Decode (to_char (sysdate,' mm ') - 1, 0, 12, to_char (sysdate, 'mm') - 1) Else '' || Decode (to_char (sysdate, 'mm') - 1, 0, 12, to_char (sysdate, 'mm') - 1) end Datev from Dual
