MongoDB : Add field in each array elements [duplicate] - mongodb

Question

This question already has answers here:
How to Update Multiple Array Elements in mongodb
(16 answers)
Closed 5 years ago.
I'm starting with mongoDB and I want to update a nested array in my documents to add some initial value, but I can't find a way to do it with mong.
here is my document :
{
"_id":"cTZDL7WThChSvsvBT",
"name":"abc",
"players":[
{
"playerName":"Name1"
},
{
"playerName":"Name2"
}
]
}
What I want to do :
{
"_id":"cTZDL7WThChSvsvBT",
"name":"abc",
"players":[
{
"playerName":"Name1",
"NewField1":0,
"NewField2":0
},
{
"playerName":"Name2",
"NewField1":0,
"NewField2":0
}
]
}
Does anyone have a solution for this kind of situation?

Answer 1

This adds the new fields to the player array ...
db.collection.update({_id: 'cTZDL7WThChSvsvBT', players: {$exists: true}}, {$set: {'players.$.NewFieldOne': 0, 'players.$.NewFieldTwo': 0}})
... but since Mongo will only update the first element of an array which matches the query you are a bit stuffed. You can, of course, choose which array element to update by using the positional operator (as in my example) or by choosing a specific element (as the previous poster suggested) but until Mongo supports 'array updates' on all elements I think you're left with a solution such as: find the relevant documents and then update each one (i.e. a client side update solution).

Answer 2

I finally found a way by editing directly the document in JS like this :
db.doc.find({_id: myDocId}).forEach(function (channel) {
channel.players.forEach(function (player) {
player.newField1 = 0;
player.newField2 = 0;
});
db.doc.update({_id: myDocId}, channel);
});

Answer 3

considering you want to update an element which is an object also,
how about this?
db.collections.updateOne({_id: "cTZDL7WThChSvsvBT"}, {$set: {"players.0.NewField1": 0, "players.0.NewField2: 0}});