Query array by stored index in document in MongoDB - mongodb

Question

I have a document like this
{
"status": {
"current": 0,
"priority": [{
"operationName": "PHOTO",
"status": "WAITING"
},
{
"operationName": "DESIGN",
"status": "NOTARRIVED"
},
{
"operationName": "COLOR_SEPARATION",
"status": "NOTARRIVED"
}]
}
}
and want to query on data like this
{
"status.priority.$status.current.operationName": {
$in: ['SERVICES', 'PHOTO']
}
}
when I query like this
{
"status.priority.0.operationName": {
$in: ['SERVICES', 'PHOTO']
}
}
it returns the data needed as the 'PHOTO' is the current operation.
I need to query based on an index of the array and this index is stored in the document in status.current
any hint?
UPDATE
After question solved I want to optimize it.

Answer 1

You can use $arrayElemAt with $expr in 3.6.
Something like
db.colname.find(
{"$expr":{
"$in":[
{"$arrayElemAt":["$status.priority.operationName","$status.current"]},
['DESIGN', 'COLOR_SEPARATION', 'PHOTO']
]
}}
)

Answer 2

For this you need to use aggregation
db.collname.aggregate([{
"$project": {
"_id": 1,
priority: { $arrayElemAt: ["$status.priority", '$status.current'] },
}
},
{
$match: {
"priority.operationName": {
$in: ['DESIGN', 'COLOR_SEPARATION', 'PHOTO']
}
}
}
])
This will work for you.
Result will be like
{
"_id" : ObjectId("5b6b656818883ec018d1542d"),
"priority" : {
"operationName" : "PHOTO",
"status" : "WAITING"
}
}