creating unique rows

Hi. I know how to do this in a script, but i'm trying to use DB commands to
do my data aquisition and creation. Here's what i'm trying to do. I have a
table with several columns, but there are 2 sets of coordinates that are of
interest (4 rows), say A1, B1, A2, B2. I would like to populate a new table
with pairs of coordinates, but only unique coordinates, A, B. Is it
possible to write a command, or several commands to add just these
coordinates? or add them all and remove the duplicates?

Thanks,

use create table <new table name> as (select DISTINCT A1, B1, A2, B2 from <old table name>);