embedded_update.rb

# Problem: Given the following document in the database, I want to update
# Dave Gahan's second prescription for Dilaudid from a quantity of 45 to
# a quantity of 30.

{ "_id" : 1
  "name" : "Dave Gahan"
  "medications" : [
    { "id" : 23,
      "name" : "Dilaudid",
      "type" : "Rx",
      "prescriptions" : [
        { "id" : 13,
          "quantity" : 60,
          "started" : 2009-01-01
        },
        { "id" : 77,
          "quantity" : 45,
          "started" : 2009-02-01
        }
      ]
    },
    { "id" : 41,
      "name" : "Oxycodone",
      "type" : "Rx"
    }
  ]
}

# First try was using 1.3.4 $ positional locator... These do not find the
# document embedded multiple levels:

collection.update(
  { "_id" : 1, "medications._id" : 23, "medications.prescriptions._id" : 77 },
  { $set : { "medications.prescriptions.$.quantity" : 30 } },
  false,
  true
)

collection.update(
  { "_id" : 1, "medications._id" : 23, "medications.prescriptions._id" : 77 },
  { $set : { "medications.$.prescriptions.$.quantity" : 30 } },
  false,
  true
)

# What I would like is to be able to match on mutliples, given a syntax like the following:

collection.update(
  { "_id" : 1, "medications._id" : 23, "medications.prescriptions._id" : 77 },
  { $set : { "medications.$0.prescriptions.$1.quantity" : 30 } },
  false,
  true
)

Any luck with this?

not yet

Got any solution for this? I'm stuck at the same point..

setModifier.$set['medications.$'] = JSON.parse({ "id" : 77, "quantity" : 45, "started" : 2009-02-01});

db.DBname.update({'_id': 1,"medications.id":77}, setModifier, function(err, updated) {
if( err || !updated ) console.log("Error: "+err);
else console.log("updated");
});
} catch (e) {
console.log("Error");
console.log(e);
}

Its working?

setModifier.$set['medications.$'] = JSON.parse({ "id" : 77, "quantity" : 45, "started" : 2009-02-01});

db.DBname.update({'_id': 1,"medications.id":77}, setModifier, function(err, updated) {
if( err || !updated ) console.log("Error: "+err);
else console.log("updated");
});
} catch (e) {
console.log("Error");
console.log(e);
}

Hello everybody,

I am really interested about finding the solution of this problem because I face the same problem like you.

Best
Loic

Stuck,too. Waiting for solutions
best wishes~~

4 years till now, is there any luck with this?

It works with "medications.$.prescriptions.0.quantity" : 30,
which means mongodb is unable to find position of nested document...

Try this... I hope this solution will help you...

collection.aggregate({$match:{_id:1}},{$unwind:'$medications'},{ $match: { 'medications.id' : 23} },function(err,result1){
if(err){
throw(err);
}else{
indexes = result1[0].medications.prescriptions.map(function(obj, index) {
if(obj.id == 13) {
return index;
}
}).filter(isFinite);
var updateData = {};
updateData["medications.$.prescriptions."+indexes[0]+".quantity"]=30;
collection.update({ _id:1,'medications.id': 23,'medications.prescriptions.id': 13 },{$set: updateData },function(err,result2){
console.log(result2);
});
}
});

There are any solution for this problem if i work with java?

for the below aggregation query it results error

assert: command failed: {
"ok" : 0,
"errmsg" : "pipeline element 3 is not an object",
"code" : 15942
} : aggregate failed

db.country_state_city.aggregate({$unwind:'$stateinfo'},{$unwind:'$stateinfo.cityinfo'},
{ $match: {$and:[{"_id":1},{ "stateinfo.state_id" : 1}]}},function(err,result1){
if(err){
throw(err);
}else{
indexes = result1[0].stateinfo.cityinfo.map(function(obj,index)
{
if(obj.city_id == 3) {
return index;
}
}).filter(isFinite);
var updateData = {};
updateData["stateinfo.$.cityinfo."+indexes[0]+".default"]=120;
db.country_state_city.update({ "_id":1,"stateinfo.state_id": 1,"stateinfo.cityinfo.city_id": 3 },
{$set: updateData },function(err,result2){
console.log(result2);
});
}

This solution (medications.$.prescriptions.0.quantity) was helpful, but arises next issue: to find index of array (in example is used "0"). As version of solution to find and retrieve index of necessary element in array as separate query and substitute inside "update query".
Any way, thank you for advice.

I don't know if there's a reason MongoDB doesn't support this, but boy would it make life so much easier...

It's 2016 and this is very much still an issue. I have created a simple workaround using the C# driver, hopefully it helps.
https://gist.github.com/dlee148/a0ec830baff5c71471213616f22cb902

any updates ?? *2017

is there any update for this?