Can I specify an existing UID in an nquad?

Users GraphQL
1

I am attaching a file to a blog post. The post can have many files. In this case, the post already exists and I am adding an extra file to it. I try specifying an existing UID and it does not like it.

mutationWriteNewFile := fmt.Sprintf(`
_:newfile <AttachedToBlogPost> "%s" .
_:newfile <FileName> "%s" .
_:newfile <MediaType> "image" .
_:newfile <created> "%s" .
_:newfile <updated> "%s" .
`, postUid, filename, timestamp, timestamp)

I have tried specifying the UID in different ways:

uid("%s")
uid(%s)
%s
"%s"

The results are always errors:

[ERROR] dgraph mutation: rpc error: code = Unknown desc = variables [0x3] not defined
[ERROR] dgraph mutation: rpc error: code = Unknown desc = variables ["0x3"] not defined
Invalid input: 0 at lexText

However, if I do the mutation as an upsert, by setting a variable beforehand, it works. Is this the only way to provide an existing UID to a new node in an nquad?

var(func: uid("%s")) {
  postUid AS HasFiles
}

Schema for reference:

type BlogPost {
    title
    body
    Files
    created
    updated
}

type File {
    AttachedToBlogPost
    FileName
    MediaType
    created
    updated
}

title: string @index(term) .
body: string @index(fulltext) .
Files: [uid] .
FileName: string .
AttachedToBlogPost: uid @reverse .
MediaType: string .
created: datetime .
updated: datetime .
2

it should be

_:newfile <AttachedToBlogPost> <%s> .

1 Like
3

Wow. I thought I had tried that, but apparently I did not. That was the solution. Thank you @MichelDiz.