MongoDB .NET Driver - Update Item in Set-CodePudding

I've got this entity:

internal record OrderBookEntity
{
    [BsonId]
    public required AssetDefinition UnderlyingAsset { get; init; }
    
    public required List<OrderEntity> Orders { get; init; }
}

which leads to this sort of document:

{
    _id: {
        Class: 0,
        Symbol: 'EURUSD'
    },
    Orders: [
        {
            _id: 'a611ffb1-c3e7-43d6-8238-14e311122125',
            Price: '-10.000000101',
            Amount: '30.000000003',
            OrderAction: 1,
            EffectiveTime: ISODate('2022-10-14T06:33:02.872Z')
        },
        {
            _id: 'a611ffb1-c3e7-43d6-8238-14e311122126',
            Price: '-10.000000101',
            Amount: '30.000000003',
            OrderAction: 1,
            EffectiveTime: ISODate('2022-10-14T06:33:08.264Z')
        }
    ]
}

I can add and remove from the Orders set without updating the whole document with:

Builders<OrderBookEntity>.Update.AddToSet(...);
Builders<OrderBookEntity>.Update.Pull(...);

I can't, however, see a way to modify one of those in place.

How would I go about changing the Amount on saying a611ffb1-c3e7-43d6-8238-14e311122125 without having to read the document, modify the collection, and update the whole thing, or just pulling and reading the order... Neither of which seems particularly performant.

CodePudding user response：

You can work with FieldDefinition by providing the field to be updated in string instead of Func expression.

MongoDB query

db.collection.update({
  "Orders._id": "a611ffb1-c3e7-43d6-8238-14e311122125"
},
{
  $set: {
    "Orders.$.Amount": "100"
  }
})