SELECT rows with unique values in two columns

Question

I have a table like this:

id          col1 col2        
----------- ---- ----------- 
1           A    5
2           A    6
3           B    5
4           B          


        

Answer 1

try the following using cursor:

create table #final (id int, col1 varchar(10), col2 int)

declare @id int, @col1 varchar(10), @col2 int
declare cur cursor for select id, col1, col2 from #t order by newid()

open cur
fetch next from cur into @id, @col1, @col2
while @@FETCH_STATUS = 0
begin
    if (@col1 in (select col1 from #final) or @col2 in (select col2 from #final))
    begin
        fetch next from cur into @id, @col1, @col2
        continue
    end
    insert into #final
    select id, @col1, @col2 from #t where col1 = @col1 and col2 = @col2 and id = @id
    fetch next from cur into @id, @col1, @col2
end

close cur
deallocate cur

select * from #final order by id

drop table #final

Result: