Get and transform merge columns

Is there anybody that can help me with getting result, I googeld it but can not find a solution on the net.

I'm trying to create a query step (or steps) that produces the following result

if column a = null and column b = "something" then take value from b
if column a = "something" and column b = null then take value from a
if column a = b then keep value (1 time, not double)

"something" can be anything but wil allways be the same if on the same row

Thanks in advance.

I found a solution

both columns : replace null with delimiter
merge using same delimiter
replace double delimiter with nothing
split on delimiter
remove un needed column (the one with the null's)

thanks for anybody who was considering helping.

hey thanks,

I'm not working so long with queries. thats indeed faster and actualy what I was looking for.

(now gonna take some painkillers for my head after hitting it so hard for not seeing that option for over 2 hours.)

few more examples and way of PowerQuery will be easy and fast