How can I convert updateMany with ArrayFilters options mongodb query into Golang? - mongodb

Question

I am facing issue to write golang code for mongodb query. I had tried to convert following mongodb query:
db.batches.updateMany(
{"batchedOrders.newOrderObject.orderDetails.trackingId" : "ORDER_JEET_2023_02_05_01"},
{ $set: { "batchedOrders.$[elem].newOrderObject.pickupDetails.note" : "Welcome" } },
{ arrayFilters: [ { "elem.newOrderObject.orderDetails.trackingId": "ORDER_JEET_2023_02_05_01" } ] }
)
Golang code:
Here b is interface{} and carrying following data:
{
"batchedOrders.$[elem].newOrderObject.dropoffDetails.recipientDetails.email": "das#rara.delivery",
"batchedOrders.$[elem].newOrderObject.orderDetails.dimensions.height": 0,
"batchedOrders.$[elem].newOrderObject.orderDetails.dimensions.length": 0,
"batchedOrders.$[elem].newOrderObject.orderDetails.dimensions.unit": "cm",
"batchedOrders.$[elem].newOrderObject.orderDetails.dimensions.width": 0,
"batchedOrders.$[elem].newOrderObject.orderDetails.orderDeliveryDetails.sla.dropoff": 1675712794,
"batchedOrders.$[elem].newOrderObject.orderDetails.parcelSize": "Medium",
"batchedOrders.$[elem].newOrderObject.orderDetails.weightDetails.billableWeight": 5,
"batchedOrders.$[elem].newOrderObject.orderDetails.weightDetails.volWeight": 5,
"batchedOrders.$[elem].newOrderObject.orderDetails.weightDetails.weight": 5,
"batchedOrders.$[elem].newOrderObject.orderDetails.weightIndex": 1,
"batchedOrders.$[elem].newOrderObject.pickupDetails.pickupIncharge.name": "Mukesh"
}
Following is the golang code:
data, _ := bson.Marshal(b)
err = bson.Unmarshal([]byte(data), &doc)
arrayFilters := options.ArrayFilters{Filters: []interface{}{bson.D{
{Key: "elem.newOrderObject.orderDetails.trackingId", Value: trackingId},
}}}
opts := options.UpdateOptions{
ArrayFilters: &arrayFilters,
}
res, err := db.Collection(BATCH_COLLECTION_NAME).UpdateMany(ctx, bson.D{{Key: "batchedOrders.newOrderObject.orderDetails.trackingId", Value: trackingId}}, bson.M{"$set": doc}, &opts)
if err != nil {
log.Println(lg.Info(err))
return false, err
}
I am getting following error:
WriteString can only write while positioned on a Element or Value but is positioned on a TopLevel
I am trying to update multiple data in mongodb database. But getting error.

Answer 1

In order to successfully use the UpdateMany method, you should do something similar to this:
package main
import (
"context"
"fmt"
"strings"
"time"
"go.mongodb.org/mongo-driver/bson"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
)
var (
ctx context.Context
cancel context.CancelFunc
)
type Message struct {
ID string `json:"id" bson:"id"`
Name string `json:"name" bson:"name"`
}
func main() {
ctx, cancel = context.WithTimeout(context.Background(), 20*time.Second)
defer cancel()
// set MongoDB connection
clientOptions := options.Client().ApplyURI("mongodb://root:root#localhost:27017")
mongoClient, err := mongo.Connect(ctx, clientOptions)
if err != nil {
panic(err)
}
defer mongoClient.Disconnect(ctx)
// select collection
collection := mongoClient.Database("demodb").Collection("myCollection")
defer collection.Drop(ctx)
fmt.Println("original documents")
// insert some random msg
if _, err := collection.InsertMany(ctx, []interface{}{
Message{"1", "John Doe"},
Message{"2", "Suzy Lee"},
Message{"3", "John Doe"},
}); err != nil {
panic(err)
}
// get records
var messagesTmp []bson.M
cursorTmp, err := collection.Find(ctx, bson.M{})
if err != nil {
panic(err)
}
if err := cursorTmp.All(ctx, &messagesTmp); err != nil {
panic(err)
}
for _, v := range messagesTmp {
fmt.Println(v)
}
fmt.Println(strings.Repeat("#", 100))
// update
var updateRes *mongo.UpdateResult
if updateRes, err = collection.UpdateMany(ctx,
bson.M{"name": "John Doe"},
bson.D{
bson.E{
Key: "$set",
Value: bson.D{
bson.E{
Key: "name",
Value: "John Doe - Edited",
},
},
},
},
); err != nil {
panic(err)
}
fmt.Println("num docs updated:", updateRes.ModifiedCount)
// list all
fmt.Println(strings.Repeat("#", 100))
fmt.Println("new documents")
var messages []Message
cursor, err := collection.Find(ctx, bson.M{})
if err != nil {
panic(err)
}
if err := cursor.All(ctx, &messages); err != nil {
panic(err)
}
for _, v := range messages {
fmt.Println(v)
}
}
Here, the relevant part is the // update section. First, we build the filter criteria we're going to use to fetch the documents to update. Then, we specify to $set a field name to a particular value John Doe - Edited.
The rest of the code is used to build a trivial program to demonstrate that the actual change is working. Feel free to adapt my example code to your specs and let me know if works for you too!