Topic: To select "unique" records
Dear colleagues, help to make request for sampling of "unique" records.
with an as ( select ' A ' a, ' B ' b ), b as ( select a, b from a union select b, a from a union select ' A ', ' A C' ) select * from b
As a result it is necessary to receive a dial-up
a b A B A A C
a b A A C B A
That is lines
to consider "identical", it is necessary to leave only one of them, (any).