Remove Subdocument items with $pull - express

Question

I'm trying to remove items from subdocuments using ExpressJS and Mongoose but it is only removing the first items, not the sub items.
So I want to remove "subitem 2" in the messages Array
This is the structure:
{
"_id" : ObjectId("5c4ee94b30ebd71cbed89a35"),
"title" : "Test",
"subitem" : [
{
"_id" : ObjectId("5c4ee95630ebd71cbed89a36"),
"title" : "Item 1",
"messages" : [
{
"_id" : ObjectId("5c4ee95f30ebd71cbed89a37"),
"type" : "single_article",
"date" : "Jan 28, 2019",
"title" : "subitem 1",
"text" : ""
}
]
},
{
"_id" : ObjectId("5c4ee96830ebd71cbed89a38"),
"title" : "item 2",
"messages" : [
{
"_id" : ObjectId("5c4ee96e30ebd71cbed89a39"),
"type" : "single_article",
"date" : "Jan 28, 2019",
"title" : "subitem 2",
"text" : ""
}
]
}
],
"__v" : 0
}
And this is the $pull method:
getController.deleteRec = function(req,res,collection){
var id = req.params.id;
console.log(id);
collection.updateOne({'subitem.messages._id': id}, {$pull: {'subitem.0.messages': {"_id": id}}}).
then(function(result){
console.log(result);
});
};
Now I know why it is only deleting the first item because I have "subitem.0.messages". How can I loop over this, so it can delete all items?

Answer 1

You can use $ as a wildcard index, removing all elements in the array matching your query like this:
{$pull: {'subitem.$.messages': {"_id": id}}}
if you want to remove multiple documents:
{$pull: {'subitem.$.messages': {"_id": {$in : [id, id2, id3...]}}}}