How to write mongo query for the object - mongodb

Question

{
"_id" : "WR10005",
"_class" : "com.bioraid.mes.model.WorkOrders",
"rountingNumber" : "R006",
"orderId" : "MR-1017",
"consumables" : "Chip",
"workOrderStatus" : "pending",
"deliveryStatus" : "on time",
"lastCompletedStage" : "testProces",
"dateAssigned" : ISODate("2017-02-17T05:38:57.631Z"),
"dateCompleted" : ISODate("2017-02-17T07:53:32.680Z"),
"opretorProcessStatus" : [
{
"opretorid" : "USER114",
"process" : "testProces",
"status" : "Done",
"workCenterId" : "WC1",
"startDate" : ISODate("2017-02-17T06:30:16.813Z"),
"endDate" : ISODate("2017-02-17T06:42:23.237Z"),
"qualityManagerReview" : {
"qaId" : "",
"status" : "Done",
"note" : ""
}
},
{
"opretorid" : "USER116",
"process" : "testProces",
"status" : "Done",
"workCenterId" : "WC1",
"startDate" : ISODate("2017-02-17T06:30:16.813Z"),
"endDate" : ISODate("2017-02-17T06:42:23.237Z")
}
],
"workOrdersRouting" : {
"testProces" : [
{
"routingStep" : "R006*010",
"operationName" : "Operation1",
"operationStatus" : "Completed",
"operationResult" : "Pass",
"operationNote" : "test"
},
{
"routingStep" : "R006*020",
"operationName" : "adalks",
"operationStatus" : "Completed",
"operationResult" : "Pass",
"operationNote" : "sddsdfsf"
}
],
"Embossing" : [
{
"routingStep" : "R006*030",
"operationName" : "Water Cleaning",
"operationStatus" : "",
"operationResult" : "",
"operationNote" : ""
}
],
"Turbidity" : [
{
"routingStep" : "R006*040",
"operationName" : "Embossing Assembly",
"operationStatus" : "",
"operationResult" : "",
"operationNote" : ""
}
]
}
}
I want to get {'opretorProcessStatus.qualityManagerReview.status' : {$ne : null}} but this is not giving proper result can any one help me to write this.
and other one is db.getCollection('workOrders').find({'opretorProcessStatus.qualityManagerReview.status' : "Done"}).

Answer 1

You can use $elemMatch to get the Document which you need.
To find documents with opretorProcessStatus.qualityManagerReview.status = Done, use this query:
db.getCollection("workOrders").find({"opretorProcessStatus":{"$elemMatch":{""qualityManagerReview.status":"Done"}}})
To find the documents which don't have status as null:
db.getCollection("workOrders").find({"opretorProcessStatus":{"$elemMatch":{""qualityManagerReview.status":{"$ne":null}}}})