Select * group by in mongo aggregation

Question

I am trying to do something that I think is quite simple. Suppose I have a series of records in mongo that have a common key, and variable number of attributes. I want to select

Answer 1

use $addToSet to the group,it will work

db.data.aggregate(
    { $group : {
            _id : "$Name",
            x: { $addToSet: "$x" },
            y: { $addToSet: "$y" },
            z: { $addToSet: "$z" },
    }}
)