Mongodb中的全外部联接查询概念

Question

如何在MongoDB中实现完全外部联接。考虑到我有两个集合，需要使用mongo查询合并为一个集合。

用户集合

{
     "_id" : 1,
     "name": "Pradeep P",
     "skll" : "Java"
}

{
     "_id" : 2,
     "name": "Umesh C",
     "skll" : "Angular"
}

会员收藏

{
     "_id" : 3,
     "name": "Shubham",
     "hobby" : "cricket"
}

{
     "_id" : 4,
     "name": "Raju",
     "hobby" : "Foodie"
}

作为具有结果的一个集合

{
     "_id" : 1,
     "name": "Pradeep P",
     "skll" : "Java"
}

{
     "_id" : 2,
     "name": "Umesh C",
     "skll" : "Angular"
}

{
     "_id" : 3,
     "name": "Shubham",
     "hobby" : "cricket"
}

{
     "_id" : 4,
     "name": "Raju",
     "hobby" : "Foodie"
}