Mongo Db数组两个键比较

Question

我有这样的集合

{
    "_id" : ObjectId("5adc0f2b2fabb719699ff257"),
    "name" : "Anil",
    "mobile" : 8108582645,
    "packages" : [
        {
            "totalAmount" : 6000,
            "purchaseDate" : ISODate("2018-04-22T04:00:00Z"),
            "expiryDate" : ISODate("2018-10-22T04:00:00Z"),
            "name" : "six month",
            "_id" : ObjectId("5adc0f2b2fabb719699ff258"),
            "isActive" : true,
            "paid" : 1000
        }
    ]
}
{
    "_id" : ObjectId("5adc0f862fabb719699ff259"),
    "name" : "Mahesh",
    "mobile" : 9877110154,
    "packages" : [
        {
            "name" : "six month",
            "expiryDate" : ISODate("2018-10-22T04:00:00Z"),
            "purchaseDate" : ISODate("2018-04-22T04:00:00Z"),
            "totalAmount" : 6000,
            "_id" : ObjectId("5adc0fa72fabb719699ff25b"),
            "isActive" : true,
            "paid" : null
        }
    ]
}

我想要所有的收藏品 package.paid === package.totalAmount

在Sql中我们喜欢这样：

select * 
from packages
where paid=total;

简而言之，我希望所有为此付费的用户。