How would I replace a value at a specific index in an array using MongoDB?
Lets say a collection for movie reviews has a rating array with individual numbers and I wanted to replace one with a new rating using only Indexes
let array = [1, 5, 3, 7]
How do I replace 5 with 4? Once again only using Indexes
Suppose, you have a document
{
"_id" : 1,
"array" : [1, 5, 3, 7]
}
then, you can update array value at specific index using dot operator
i.e, array.<index>
with $set operator
db.collection.update(
{ /*match query*/ },
{ $set: { "array.1": 4 } } // array.index where index=0,1,2,...
)
The Updated Document becomes,
{
"_id" : 1,
"array" : [1, 4, 3, 7]
}
You need to concatenate the index in key. Try this
{ _id: editedObj.id }, // Match id.
{ $set: { [`reviews.${index}`]: editedObj.reviews}})
{ _id: editedObj.id }, // Match id. { $set: { "reviews.index": editedObj.reviews}}); I am using node.js, when i try doing that using a variable with my index value it gives me an error. Any idea what i'm doing wrong?
Cannot create field '${index}' in element {reviews: [ "test" ]}let updated = await Movie.updateOne( { _id: editedObj.id }, // Match id. { $set: { "reviews.${index}": editedObj.reviews}});