Get existing and inserted IDs in upsert operation (db.Clauses clause.OnConflict) - postgresql

Question

I have a scenario where I need to insert into a table some array of data, In which case if the combination of name and version already exists (composite unique constrain), I need to get those IDs, else get inserted IDs, if both case exist get inserted and existing ids
Models and code I tried are given below:
Model Dependency
type Dependency struct {
gorm.Model
ID string `gorm:"primaryKey; not null"`
Name string `gorm:"not null; UniqueIndex:idx_name_version"`
Version string `gorm:"not null; UniqueIndex:idx_name_version"`
}
go code with gorm query to insert dependencies
var saveDependencyData []models.Dependency
// Dependecies are read form api input
// [
// {
// "name": "node",
// "version": "16.0.0"
// },
// {
// "name": "node",
// "version": "18.0.0"
// }
// ]
for _, dep := range Dependecies {
saveDependencyData = append(saveDependencyData, models.Dependency{
ID: nanoid.New(),
Name: dep.Name,
Version: dep.Version,
})
}
res := db.Clauses(clause.OnConflict{
Columns: []clause.Column{{Name: "name"}, {Name: "version"}},
DoUpdates: clause.AssignmentColumns([]string{"name"}),
}).Create(saveDependencyData)
gorm query output
INSERT INTO "dependencies" ("id","created_at","updated_at","deleted_at","name","version") VALUES ('QanL-nfNFrOGdxG2iXdoQ','2022-10-06 19:21:13.079','2022-10-06 19:21:13.079',NULL,'react','16.0.0'),('Yw1YyQ-aBqrQtwZ72GNtB','2022-10-06 19:21:13.079','2022-10-06 19:21:13.079',NULL,'react','18.0.0') ON CONFLICT ("name","version") DO UPDATE SET "name"="excluded"."name" RETURNING "id"
This query returns the list of ids I needed, but could not find a way to retrieve that.
using Scan() gets all the datas in that table.
Either you can help with a way to retrieve the returning IDs form the above GORM db.Clauses(), Or any other optimized method to get those (inserted & existing) ids with a upsert query.

Answer 1

As indicated in the comments: Several functions of GORM expect a pointer as argument and will update the variable with information.
That's obviously the case for all functions whose main purpose is to retrieve information (First, Find, ..., cf. https://gorm.io/docs/query.html).
But it's also the case for functions that modify data like
Create (https://gorm.io/docs/create.html),
Update (https://gorm.io/docs/update.html#Returning-Data-From-Modified-Rows) or
Delete (https://gorm.io/docs/delete.html#Returning-Data-From-Deleted-Rows)
So, the solution in this case is to pass Create(&saveDependencyData) instead of Create(saveDependencyData).
The up-to-date information corresponding to the database will then be available in the saveDependencyData after the call.