postgresql - SQL rows to Column values -

i have scenario purchase can paid either cash,card or voucher above three. need report show payment types in seperate lines captured these value in single row. problem how transfer rows values columns .

for ex.

╔═════════════════════════════════════════════════════╗ ║ order           amount     cash     card    voucher ║ ╠═════════════════════════════════════════════════════╣ ║ purchase1       1000       500      300     200     ║ ╚═════════════════════════════════════════════════════╝ 

but need result has

╔══════════════════════════════════╗ ║ order           amount  paytype  ║ ╠══════════════════════════════════╣ ║ purchase1        500     cash    ║ ║ purchase1        300     card    ║ ║ purchase1        200     voucher ║ ╚══════════════════════════════════╝ 

let can provide suggestions accomplish above format.

i suggest use union all this:

select order, cash amount, 'cash' paytype union select order, card, 'card' union select order, voucher, 'voucher'