Getting corners of polygon in latitude and longitude using PostGIS?

How can I get the corners of a polygon -a square/rectangle, to be precise- in latitude-longitude format by using its geom value -or some other way, using PostGIS?

Answer

ST_extent(geom) You will receive left, bottom, right and top value. Combining them you will get corners

http://postgis.net/docs/ST_Extent.html