Function insert_with_id 

pub async fn insert_with_id(
    conn: &mut PgConnection,
    id: Uuid,
    name: &str,
    path: &str,
    mime: &str,
    uploader: Option<Uuid>,
    size_bytes: Option<i64>,
) -> ModelResult<()>

Records a stored object under an id the caller has already chosen.

For paths that contain the id: the object reaches the store before this row exists, so a path built from the row’s own id has to be settled first. Everything else wants insert.