I have the following code:
<db.collection>.find({ id : { $exists: true } })
this returns all documents with a id property.
how can I make it return an array with all the values of that id? Example:
{_id: ---, id: 21162 }
{_id: ---, id: 23712 }
returns: [21162, 23712]
PS: I thought about using a repetition structure that would go through all the properties and push an array, but I think it’s unnecessary and I think it’s not the best way to do this
You can do the following,
let data = [
{'_id': '---', 'id': '21162' },
{'_id': '---', 'id': '23712' }
];
let result = data.map(item => item.id);
console.log(result);There are two options to achieve this:
The first one is to let Mongoose/MongoDB filter them, using the projection param:
// executes, name LIKE john and only selecting the "name" and "friends" fields
await MyModel.find({ name: /john/i }, 'name friends').exec();
this is an example from the docs, here: https://mongoosejs.com/docs/api.html#model_Model.find
The other option is what Sabbir suggested, but it requires the whole list of documents returned by Mongoose to be loaded into memory and be processed one element at a time.
