MongoDB with the Go driver

Uses mongo-go-driver v2.9. The code is an ordinary application for the original database; nothing in it knows about MachNoSQL.

The only change

mongodb://app:secret@mongo.example.com:27017/shop?authSource=admin
mongodb://app:secret@machnosql.example.com:27017/shop?authSource=admin

The address comes from the environment variable MONGODB_URI, so switching to MachNoSQL changes configuration only.

Run

export MONGODB_URI='mongodb://app:secret@machnosql.example.com:27017/shop?authSource=admin'
go mod tidy
go run .

Source

The program as it is kept and tested in the Mach Database NoSQL repository; highlighted lines read the connection setting.

main.go

// Orders example for MongoDB, unchanged on MachNoSQL.
package main

import (
  "context"
  "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() {
  ctx := context.Background()
  client, err := mongo.Connect(options.Client().ApplyURI(os.Getenv("MONGODB_URI")))
  if err != nil {
    log.Fatal(err)
  }
  defer func() { _ = client.Disconnect(ctx) }()

  orders := client.Database("shop").Collection("orders")
  if _, err := orders.DeleteMany(ctx, bson.D{}); err != nil {
    log.Fatal(err)
  }
  _, err = orders.InsertMany(ctx, []any{
    bson.D{{Key: "customer", Value: "ada"}, {Key: "item", Value: "keyboard"}, {Key: "qty", Value: 1}, {Key: "price", Value: 49.0}},
    bson.D{{Key: "customer", Value: "ada"}, {Key: "item", Value: "mouse"}, {Key: "qty", Value: 2}, {Key: "price", Value: 19.5}},
    bson.D{{Key: "customer", Value: "linus"}, {Key: "item", Value: "monitor"}, {Key: "qty", Value: 1}, {Key: "price", Value: 199.0}},
  })
  if err != nil {
    log.Fatal(err)
  }

  var mouse bson.M
  if err := orders.FindOne(ctx, bson.D{{Key: "item", Value: "mouse"}}).Decode(&mouse); err != nil {
    log.Fatal(err)
  }
  fmt.Println(mouse)

  update := bson.D{{Key: "$inc", Value: bson.D{{Key: "qty", Value: 1}}}}
  if _, err := orders.UpdateOne(ctx, bson.D{{Key: "item", Value: "mouse"}}, update); err != nil {
    log.Fatal(err)
  }

  pipeline := mongo.Pipeline{
    {{Key: "$group", Value: bson.D{
      {Key: "_id", Value: "$customer"},
      {Key: "revenue", Value: bson.D{{Key: "$sum", Value: bson.D{{Key: "$multiply", Value: bson.A{"$qty", "$price"}}}}}},
    }}},
    {{Key: "$sort", Value: bson.D{{Key: "revenue", Value: -1}}}},
  }
  cursor, err := orders.Aggregate(ctx, pipeline)
  if err != nil {
    log.Fatal(err)
  }
  var rows []bson.M
  if err := cursor.All(ctx, &rows); err != nil {
    log.Fatal(err)
  }
  fmt.Println(rows)
}

go.mod

module example.com/machnosql/mongodb

go 1.25

require go.mongodb.org/mongo-driver/v2 v2.9.2