Initially, your update() query is not correct..
To understand how to update documents properly, refer to the documentation available here
Model.update(conditions, update, options, callback);
If your current database model consists of documents like this (as mentioned in your question):
[
{
"_id": 1,
"value": 50
},
{
"_id": 2,
"value": 100
}
];
and you have an array that contains objects (docs) to be modified with the current db's docs:
idsArray: [
{
"_id": 1,
"value": 4
},
{
"_id": 2,
"value": 27
}
];
In my experience with mongodb & mongoose, updating all docs with a single line query may not be possible.. (P.S. I am uncertain about this..)
However, to make your code function correctly, you will need to do something like this:
Approach: Iterate over each doc in the docs i.e., idsArray and execute update() for each one.
Here's how you can achieve this:
idsArray.forEach(function(obj) {
Model.update({_id: obj._id}, {$set: {value: obj.value}});
});
In the above code, I am assuming that your db docs have _id values structured as shown above (i.e., "_id": 1).. If they are represented differently like "_id": ObjectId('1')
[
{
"_id": ObjectId('1'),
"value": 50
},
.....
.....
]
then you would need to convert _id to ObjectId(obj._id) in the update() query..
you can achieve this by using the following method.
var ObjectId = require('mongodb').ObjectID;
idsArray.forEach(function(obj) {
Model.update({_id: ObjectId(obj._id)}, {$set: {value: obj.value}});
});
P.S. Please ensure the format of _id before proceeding further..
I trust this information proves to be helpful.
Cheers,