mongodb-go-driver/bson struct to bson.Document encoding

Question

I\'m working with https://github.com/mongodb/mongo-go-driver and currently trying to implement a partial update of such struct

type NoteUpdate struct {
    ID            


        

Answer 1

Unfortunately this is currently not supported.

You may create a helper function which "converts" a struct value to a bson.Document like this:

func toDoc(v interface{}) (doc *bson.Document, err error) {
    data, err := bson.Marshal(v)
    if err != nil {
        return
    }

    err = bson.Unmarshal(data, &doc)
    return
}

Then it can be used like this:

partialUpdate := &NoteUpdate{
    Title: "Some new title",
}

doc, err := toDoc(partialUpdate)
// check error

res := c.FindOneAndUpdate(
    context.Background(),
    bson.NewDocument(bson.EC.String("_id", "some-note-id")),
    bson.NewDocument(bson.EC.SubDocument("$set", doc)),
)

Hopefully ElementConstructor.Interface() will improve in the future and allow passing struct values or pointers to struct values directly.