[Question] Many2Many insert on new parent fails foreign key constraint

[paulinevos]

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Your Question

It is unclear to me how, if at all, I can insert a new parent entity holding a nested many2many association while still being able to maintain a foreign key constraint on the association table, i.e.:

type User struct {
  Languages: []Language `gorm:"many2many:user_language"`
}

type Language struct {
  Key string
}

user := User{
  Languages: []Language{{Key: "nl-NL"}}
}

db.Save(&user)  // Will fail on an fk constraint violation for user ID, as the user does not exist yet.

To be clear I understand I could Append the languages after first saving the user, but imo it would be desired behavior to be able to create a new entity with nested entities directly instead of having to append them separately after the Save.

Expected answer

How to achieve this if at all possible, and if not, would it be possible to open a feature request

[paulinevos]

Worth noting: if you agree I'd be happy to contribute this myself if it's missing :)