Go 드라이버 빠른 시작

package main
import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"go.mongodb.org/mongo-driver/v2/bson"
	"go.mongodb.org/mongo-driver/v2/mongo"
	"go.mongodb.org/mongo-driver/v2/mongo/options"
)
func main() {
	uri := os.Getenv("MONGODB_URI")
	docs := "www.mongodb.com/docs/drivers/go/current/"
	if uri == "" {
		log.Fatal("Set your 'MONGODB_URI' environment variable. " +
			"See: " + docs +
			"usage-examples/#environment-variable")
	}
	client, err := mongo.Connect(options.Client().
		ApplyURI(uri))
	if err != nil {
		panic(err)
	}
	defer func() {
		if err := client.Disconnect(context.TODO()); err != nil {
			panic(err)
		}
	}()
	coll := client.Database("sample_mflix").Collection("movies")
	title := "Back to the Future"
	var result bson.M
	err = coll.FindOne(context.TODO(), bson.D{{"title", title}}).
		Decode(&result)
	if err == mongo.ErrNoDocuments {
		fmt.Printf("No document was found with the title %s\n", title)
		return
	}
	if err != nil {
		panic(err)
	}
	jsonData, err := json.MarshalIndent(result, "", "    ")
	if err != nil {
		panic(err)
	}
	fmt.Printf("%s\n", jsonData)
}