I'm trying to find a document by its auto generated _id field. Code below returns nothing:
var documentID bson.RawValue
documentID.Type = 7
documentID.Value = []byte("5c7452c7aeb4c97e0cdb75bf")
objID := documentID.ObjectID()
value := collection.FindOne(ctx, bson.M{"_id": objID})
The value I provided is a real document id I got from Mongo Express
"_id": ObjectID("5c7452c7aeb4c97e0cdb75bf")
In case you're wondering why I bother with RawValue, I found examples using bson.EC.ObjectID but bson package doesn't seem to have EC type, also I found some examples mentioning github.com/mongodb/mongo-go-driver/bson/objectid package, but I could not find that package either. I previously developed with mgo but I'm new to mongo-go-driver, so if you can point an easy way to declare an ObjectID.
As @Carlos mentioned, I changed my code as this and everything works well.
objID, _ := primitive.ObjectIDFromHex("5c7452c7aeb4c97e0cdb75bf")
value := collection.FindOne(ctx, bson.M{"_id": objID})
You can use some thing like this:
var userDB user
objectIDS, _ := primitive.ObjectIDFromHex(userID)
collectionUser := dBClient.Database("MyDatabase").Collection("Users")
filter := bson.M{"_id": objectIDS}
err := collectionUser.FindOne(ctx, filter).Decode(&userDB)
if err != nil {
fmt.Println("errror retrieving user userid : " + userID)
}
package main
import (
"fmt"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/bson/primitive"
"context"
)
// get collection "users" from db() which returns *mongo.Client
var userCollection = db().Database("goTest").Collection("users")
func mongodriver_find_by_id() {
objectId, err1 := primitive.ObjectIDFromHex("6041c3a6cfcba2fb9c4a4fd2")
if err1 != nil {fmt.Println(err1)}
findone_result := userCollection.FindOne(context.TODO(), bson.M{"_id":objectId})
var bson_obj bson.M
if err2 := findone_result.Decode(&bson_obj); err2 != nil {fmt.Println(err2)}
fmt.Println("bson_obj:", bson_obj)
}
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