scratch.go

package main

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"os"
	"time"

	"github.com/joho/godotenv"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	godotenv.Load(".env")
	uri := os.Getenv("MONGODB_URI")
	if uri == "" {
		log.Fatal("MONGODB_URI not set")
	}

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()

	client, err := mongo.Connect(ctx, options.Client().ApplyURI(uri))
	if err != nil {
		log.Fatal(err)
	}
	defer client.Disconnect(ctx)

	coll := client.Database("systemDesign").Collection("System_Design_Full_notes")

	var result bson.M
	err = coll.FindOne(ctx, bson.M{"chapter_no": 10}).Decode(&result)
	if err != nil {
		log.Fatal(err)
	}

	b, _ := json.MarshalIndent(result, "", "  ")
	fmt.Println(string(b))
}