This site uses different types of cookies, including analytics and functional cookies (its own and from other sites). To change your cookie settings or find out more, click here. If you continue browsing our website, you accept these cookies.
We've recently made an accessibility improvement to the community and therefore posts without any content are no longer allowed. Please use the spoiler feature or add a short message in the message body in order to submit your weekly challenge.
Struggled with this one, I think I knew I needed some kind of cartesian join, which in my head meant Append Fields, but I then struggled to filter out all the cases that weren't needed. Turns out a simple L-R join did the job much better because you can join by UserID. Then it was a relatively simple job to filter out inverted pairs and left=right cases.