MongoDB update query in subarray

Question

An update in the array of objects inside another array of objects.

mongodb field that I'm working on:

otherFields: values,

tasks: [
 {
  _id: mongodb.objectID(),
  title: string,
  items:[{
   _id: mongodb.objectID(),
   title: string,
   completed: boolean        //field need to be update.
  }]
 },
 {}...
],

otherFields: value

sample mongodb document

I need to find the document using the task_id and the item_id and update a completed field in item of a task. Using the mongoose findOneAndUpdate method

const path = "tasks.$.items." + item_id + "completed";
collectionName.findOneAndUpdate( 
{ _id: req.user._id, "tasks._id": taskID }, 
{ $set: { [path]: true }}); 

The above query doesn't work!!!

Answer 1

There is no need to use multiple query conditions, since you'd like to update a specific item that has an unique ID. Therefore you could use something along the lines:

collectionName.findOneAndUpdate(
  { 'tasks.items._id': itemID },
  ...
);

Keep in mind this structure is far away from optimized as it would basically look through the entire database...

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Also now that I think of it, you'd also have issue with the update, as there are two nested arrays within the document. Read more here: How to Update Multiple Array Elements in mongodb