Tentei isso:
db.countries.aggregate(
{
"$project": {
"state": "$states",
"_id": 0
}
},
{
"$unwind": "$state"
},
{
"$group": {
"_id": "$state.name",
"state": {
"$first": "$state"
}
}
},
{
"$match": {
"_id": "orissa"
}
}
);
E pegou:
{
"result" : [
{
"_id" : "orissa",
"state" : {
"name" : "orissa",
"direction" : "east",
"population" : 41947358,
"districts" : [
{
"name" : "puri",
"headquarter" : "puri",
"population" : 1498604
},
{
"name" : "khordha",
"headquarter" : "bhubaneswar",
"population" : 1874405
}
]
}
}
],
"ok" : 1
