I think you have to do a query to pass existing rows to delete or delete_all,
because they require the Ecto metadata element of the struct to contain the ‘loaded’ flag.
The only alternative would be to completely fake the whole struct,
including all the internal fields and flags.
But I agree with you that there should be a version of delete,
which just takes a primary key value, by analogy with the ‘get’ function.
