Please help with decoding key _id to primitive.ObjectID in go

Working with Data Drivers
4

@Goshleg_N_A Is it possible you’re mixing Go Driver v1.x and v2.x packages? I was able to reproduce the error you’re seeing with this example:

package main

import (
	"context"

	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/v2/bson"
	"go.mongodb.org/mongo-driver/v2/mongo"
)

func main() {
	mongoClient := mongo.Connect()

	type User struct {
		ID           primitive.ObjectID `json:"_id" bson:"_id,omitempty"`
		Username     string             `bson:"username"`
		PasswordHash string             `bson:"password_hash"`
	}

	usersCollection := mongoClient.Database("test").Collection("users")

	ctx := context.TODO()
	user := User{
		Username:     "anyuser",
		PasswordHash: "somehash",
	}
	if _, err := usersCollection.InsertOne(ctx, user); err != nil {
		panic(err)
	}

	var userResult User
	err := usersCollection.FindOne(ctx, bson.D{}).Decode(&userResult)
	if err != nil {
		panic(err)
	}
}

Notice that primitive.ObjectID comes from the non-v2 package. Try changing that type to bson.ObjectID and see if it resolves your problem.