I have a basic document versioning system. While updating a record, I should save the current field value in another field(as a list/array, so we going to use $push in MongoDB).
For example, if I want to update the user_name field, the current name should be saved to old_user_names
sample code
func UpdateDocument(ctx context.Context, id uuid.UUID, obj interface{}) error {
filter := bson.M{"_id": id}
update := bson.M{"$set": obj,
"$push": bson.D{
{"old_original_names", "old_original_name_here"},
},
"$inc": bson.M{"version": 1}}
r.db.FindOneAndUpdate(ctx, filter, update)
return nil
}
I should add the current object's name field to "current_name_here" but I couldn't figured it out.
Related
I have this data schema:
"person": { "name": "Neeraj", "hobbies": ["movies" ] }
This is the struct to insert the document in MongoDB
type Person struct {
Id primitive.ObjectID `bson:"_id,omitempty" json:"id,omitempty"`
Name string `bson:"name,omitempty" json:"name,omitempty"`
Hobbies []string `json:"hobbies,omitempty" bson:"hobbies,omitempty"`
}
When PUT person API is called without the hobbies field, I would expect it to not update the hobbies field in DB. In this case when I parse the body, the struct has Hobbies set as null and because of 'omitempty' bson tag, it does not update the hobbies field in DB, which is fine.
filter := bson.D{{"_id", oid}}
update := bson.M{
"$set": record,
}
result, err := collection.UpdateOne(ctx, filter, update)
However, when PUT person API is called with the hobbies field set to an empty array, I would expect it to update the hobbies field and set it to empty. But in this case too, the record struct has hobbies field set to null, and it doesn't update the hobbies field.
How do I do this in go, so that my code caters to all of following update payload? I am using golang official mongo driver.
{
"name": "john" // Should not modify the hobbies field.
}
{
"name": "john",
"hobbies": [] // // Should update the hobbies field to an empty array
}
It sounds like you want to merge the person object based on what was provided in the request, whereas the MongoDB $set operator, "replaces the value of a field with the specified value." Because MongoDB doesn't understand how complex types should be merged, you'll have to specify the exact merging logic yourself.
filter := bson.M{"_id": oid}
set := bson.M{
"name": record.Name,
}
if (record.Hobbies) != nil {
set["hobbies"] = record.Hobbies
}
update := bson.M{"$set": set}
I'm trying to append fields to an object in my mongodb collection. So far this is what my document in MongoDB looks like.
My users can have multiple devices so I'm trying to append more fields to the devices object. I have tried to use $push for an array instead of an object but I didn't like how I would have to access the data later on when I retrieve it from the database.
So I started to use $set. $set works great because it gives me the format in which I want my data to save in the db but it will continually override my one key value pair in the devices object every time and I don't want that to happen.
db.go
func AddDeviceToProfile(uid string, deviceId int, deviceName string) {
client := ConnectClient()
col := client.Database(uid).Collection("User")
idString := strconv.Itoa(deviceId)
filter := bson.M{"uid": uid}
update := bson.M{
"$set": bson.M{"devices": bson.M{idString: deviceName}}, <------ Need to fix this
}
option := options.FindOneAndUpdate()
_ = col.FindOneAndUpdate(context.TODO(), filter, update, option)
log.Print("Device Added")
_ = client.Disconnect(context.TODO())
}
I have looked into using $addFields but I don't know if I was doing it correctly I just replaced $set above and added $addFields and I also tried it this way
update := bson.M{
"devices": bson.M{"$addFields": bson.M{idString: deviceName}},
}
What I want my document to look like
Instead of using $push or $addFields what you need is $set directive.
To specify a field in an embedded document, use dot notation.
For the document matching the criteria _id equal to 100, the following operation updates the make field in the devices document:
db.products.update(
{ _id: 100 },
{ $set: { "devices.make": "zzz" } }
)
Converting them to Go syntax is easy as well. What you are doing is correct. The following should work or might require a little bit of tweaking.
func AddDeviceToProfile(uid string, deviceId int, deviceName string) {
client := ConnectClient()
col := client.Database(uid).Collection("User")
idString := strconv.Itoa(deviceId)
filter := bson.M{"uid": uid}
update := bson.M{"$set": bson.M{"devices." + idString: deviceName}}
option := options.FindOneAndUpdate()
_ = col.FindOneAndUpdate(context.TODO(), filter, update, option)
log.Print("Device Added")
_ = client.Disconnect(context.TODO())
}
I want to update some fields in DB and also want to it to return some fields, can you suggest how to retrieve the return fields?
so i am using here,
returnFields := map[string]interface{}{"order_id":1}
data := FindAndUpdateVerticalsOffers(updateQuery, updateFields, returnFields)
How to get order_id from "data":
func FindAndUpdateVerticalsOffers(updateQuery map[string]interface{}, updateFields interface{}, returnFields map[string]interface{}) map[string]interface{} {
session := db.GetSession()
defer session.Close()
collection := session.DB("").C(VerticalsOffersName)
updateSet := bson.M{"$set": updateFields}
return collection.FindOneAndUpdate(updateQuery, updateSet, returnFields)
}
I want to update some fields in DB and also want to it to return some fields,
If you're using mongo-go-driver (currently v1.1), you can utilise FindOneAndUpdate() which finds a single document and updates it, returning either the original or the updated.
The method accepts argument for FindOneAndUpdateOptions, which supports projection. For example:
collection := client.Database("dbName").Collection("collName")
// Sets projection (or return fields)
findUpdateOptions := options.FindOneAndUpdateOptions{}
findUpdateOptions.SetProjection(bson.M{"order_id": 1})
result := collection.FindOneAndUpdate(context.TODO(),
bson.M{"foo":1},
bson.M{"$set": bson.M{"bar":1}},
&findUpdateOptions)
doc := bson.M{}
err = result.Decode(&doc)
The above query will match a document where field foo is 1, update field bar to 1, and return only order_id as the result. Note that by default the _id field is also returned. You can suppress the _id field from being projected by setting it to 0.
Please note that the return type of FindOneAndUpdate is a SingleResult object, which represents a single document returned from an operation. If the operation returned an error, the Err method of SingleResult will return that error.
I am so frustrated with the Official MongoDB for Go. There is really no documentation. I am trying to update more than one field in a collection. All references, as normal are the simplest and updating one field:
update := bson.D{bson.E{"$set", bson.E{"releaseimage", r.ReleaseImage}}}
That works. I have tried various ways to expand that to set two fields and get errors:
update := bson.D{
{"$set",
bson.E{"releaseimage", r.ReleaseImage},
//bson.E{"releasepath", r.ReleasePath},
},
// {"$set",
// bson.E{
// "releasepath", r.ReleasePath}},
}
the first one remove the comments in the first set. invalid syntax for second attempt remove the comments on the second set. invalid syntax.
I am at a loss. To keep going I am doing two updates, one right after another. Inefficient.
Thank you.
For multiple fields, you have to create an array of bson element(bson.E). then append/assign as many fields you want in array item.
var update []bson.E
if r.ReleaseImage != "" {
update = append(update, bson.E{"releaseimage", r.ReleaseImage})
}
if r.Releasepath != "" {
update = append(update, bson.E{"releasepath", r.Releasepath})
}
// now update db
result, err := coll.UpdateOne(
context.Background(),
bson.D{
{"id", r.ID},
},
bson.D{
{"$set", update},
{"$currentDate", bson.D{
{"updated", true},
}},
},
)
Hope this helps
Simply do like this:
uQuery := make(bson.M)
if len(r.ReleaseImage)>0{
uQuery["releaseimage"]=r.ReleaseImage
}
if len(r.Releasepath)>0{
uQuery["releasepath"]=r.Releasepath
}
updateQ := make(bson.M)
updateQ["$set"] = uQuery
Now simply pass 'updateQ' to mongodb update Wrapper function along with findQuery.
I'm Using Mongo Go Adapter: github.com/mongodb/mongo-go-driver/
I'm trying different patterns but none of them working for me.
//ref struct
type userbase struct {
Name string `bosn:"Name"`
Coins int `bson:"Coins"`
}
//ref code, it's updating _id, but not updating a value
filter := bson.M{"name": "Dinamis"}
update := bson.D{{"$inc", bson.M{"Coins": 1}}}
db := Client.Database("Nothing").Collection("dataUser")
db.UpdateOne(context.Background(), filter, update)
//update filters that i also used
update := bson.D{{"$inc", bson.D{{"Coins", 1},}},}
//simple ways was tryed also
update := &userbase{name, amount} //should i try *userbase{} ?
//Also i'm tryed
ReplaceOne()
FindOneAndReplace()
FindOneAndUpdate()
it's hard to dig deeper b-cuz of luck of actual documentation: https://docs.mongodb.com/ecosystem/drivers/go/
Thanks #Wan Bachtiar for answering this in official MongoDB-go-adapter group.
By default queries in MongoDB is case sensitive on the field name. In
your struct you defined the field to be Name, but in your filter to
specify name. This would result in no documents matching the query
predicates for the the update operation. For example, if you have a
document as below:
{ "_id": ObjectId("..."), "Name": "Dinamis", "Coins": 1 }
You can perform an update to increment the number of Coins using below
snippet:
collection := client.Database("Nothing").Collection("dataUser")
filter := bson.M{"Name": "Dinamis"}
update := bson.D{{"$inc", bson.M{"Coins": 1}}}
result, err := collection.UpdateOne(context.TODO(), filter, update)
Also, note that you have a typo on the bson tag in your struct. It’s
supposed to be bson:"Name" not bosn:"Name". You may find Query
Documents as a useful reference (Select the Go tab to show examples in
Go)
Regards, Wan.