Complex Logic quires on simple mongo document - mongodb

Question

I am battling with forming complex logic queries on very basic data types in mongo. Essentially I can have millions of user attributes so my basic mongo document is:
{
name: "Gender"
value: "Male"
userId : "ABC123"
}
{
name: "M-Spike"
value: 0.123
userId : "ABC123"
}
What I would like to do is search for things like findAll userId where {name : "Gender, value: "Male"} AND { name : "m-spike", value : { $gt : 0.1} }
I have tried using the aggregation framework but the complexity of the queries is limited, basically I was ORing all the criteria and counting the results by sampleId (which replicated a rudimentary AND)

Answer 1

I can see a way to do it for N being the number of attributes you want to query about (N being 2 in your example). Try something like this:
db.collection.aggregate(
[ { $match: {$or: [
{"name":"M-Spike","value":{$gt:.1}},
{"name":"Gender","value":"Male"}
]
}
},
{ $group: { _id:"$userId",total:{$sum:1}}
},
{ $project: { _id:1,
matchedAttr : { $eq: ["$total",2] }
}
}
]
)
You will get back:
{
"result" : [
{
"_id" : "XYZ123",
"matchedAttr" : false
},
{
"_id" : "ABC123",
"matchedAttr" : true
}
],
"ok" : 1
}
Now, if you had 2 conditions you matched via "$or" then you get back true for _id that matched both of them. So for five conditions, your $match: $or array will have five conditional pairs, and the last $project transformation will be $eq: ["$total",5]
Built in to this solution is the assumption that you cannot have duplicate entries (i.e. _id cannot have "M-Spike":.5 and also "M-Spike":.2. If you can, then this won't work.