How can I append value to a list predicate

Users Dgraph
,
2

My fault, the document had say about this: list type

So my solution is:

upsert {
  query {
    q(func: eq(user_name, "xxxx")) {
      v as uid
    }
  }

  mutation {
    set {
      uid(v) <projects> <0x9c44> .
    }
  }
}

It will append <0x9c44> to the user’s projects list predicate