mongo db how to store multi relation like graph - mongodb

Question

I have to store some users and their group relations like below
So I am planning to create a collection like below
UserGroupRelation Collections
{
"user":String,
"Group":String"
}
example of collections for Super admin users
{
"user":"Adminuser-1",
"Group":"Group1"
}
{
"user":"Adminuser-1",
"Group":"Group2"
}
{
"user":"Adminuser-1",
"Group":"Group3"
}
where user & Group column is indexed and I will run below kind of query
1.Whenever I want to check whether given user has access to the given group
db.UserGroupRelation.find( { user: "Adminuser-1", Group: "Group2" })
2.Also I want to delete all the association whenever we delete group
db.UserGroupRelation.deleteMany({ Group: "Group2" })
3.Also find all the users of a group
db.UserGroupRelation.find( { Group: "Group2" })
4.Find Hierarchy?, with my Approach I am not able to find
But with this approach I am duplicating lot of data also in real time I may have 10000 groups and 1 million user so there would be performance issue. And with this I am not able to maintain a hierarchy like SuperAdmin->SubAdmin->user of same group
I checked with mongo tree but it is not fitting to this requirement. is there a better way to handle this requirement in mongodb .?

Answer 1

This is the structure your graphic requirements show. It does still lead to repetition though so you will need to change it. Read up on one-many relationships.
{
"superAdmin_ID": "001",
"groups": [
{
"_id": "0",
"groupNumber": "1",
"users": [
{
"_userKey": "1023"
"userName": "Fred"
},
{
"_userKey": "1024"
"userName": "Steve"
}
],
"subAdmin": {
"_adminKey": "55230"
"adminName": "Maverick"
},
},
{
"_id": "1",
"groupNumber": "2",
"users": [
{
"_userKey": "1023"
"userName": "Fred"
},
{
"_userKey": "4026"
"userName": "Ella"
}
],
"subAdmin": {
"_adminKey": "55230"
"adminName": "Maverick"
},
},
{
"_id": "2",
"groupNumber": "3",
"users": [
{
"_userKey": "7026"
"userName": "James"
}
],
"subAdmin": {
"_adminKey": "77780"
"adminName": "Chloe"
},
},
]
}
You can also make subAdmin an array if you need more than one subAdmin within a group.