sql - get only month and year from date -

i want year, , numeric month date, try month char month, how can numeric month, , year ?

select to_char(dateper,'mon')  calcul  group dateper 

you can numeric representation in string using:

select extract(year dateper) yyyy, extract(month dateper) mm calcul group yyyy, mm; 

or:

select to_char(dateper, 'yyyy-mm')  calcul group to_char(dateper, 'yyyy-mm') ;