Here is a sample of my database:
What I have to do is getting all possible pairs of "start station name" and "end station name" and count with a sum all the made trips of this pair, then sort these pairs by the total of made trips. I already know how to sum by group then sort. However, I don't know and haven't found if MongoDB has easy functions to make these unique value pairs.
The aim is to get the most used trips paths, and make recommandations following insights.