test for aggregating outstanding orders from mongo shell

aggregate-outstanding.js

db.getCollection('Orders').aggregate([
    {
        '$match' : { 'products.outstanding' : { $gt: 0 }, 'status' : {$nin:['cancelled', 'dispatched']} }
    },
    {
        '$unwind' : '$products'
    },
    {
        '$group' : {
            '_id': '$products._id',
            outstanding: {
                '$sum' : '$products.outstanding'
            },
            totalOrders: {
                '$sum' : NumberInt(1)
            },
            ids: {
                '$addToSet' : '$_id'
            }
        }
    }
])

data-structure.json

// Several fields omitted
// This is a mongo document
// In reality comments aren't allowed
{
    "_id" : ObjectId("id-here"),
    "id" : 1,// used for display to users only
    "products" : [ 
        {
            "_id" : "product-mongo-id",
            "quantity" : 15,
            "outstanding" : 10,
            "allocations" : [ 
                {
                    "_id" : "stock-mongo-id",
                    "number" : 5
                }
            ]
        }
    ],
    "customer" : "mongo-id",
    "deliveryAddress" : "address-id",
    "date" : ISODate("2017-08-30T14:52:32.684Z"),
    "lastUpdated" : ISODate("2017-08-30T14:52:32.684Z"),
    "origin" : "origin-id",
    "status" : "in-progress"
}

find-outstanding.js

db.getCollection('Orders').find({'products._id':'mongo-id-of-product', 'products.outstanding' : { $gt: 0 }}, { 'products.$.outstanding' : 1})