When I write "select field" I am saying which field I want to return from the query and which field I want to group by. There's no difference. And the DBMS enforces that there is no difference. *
* Except for the special case when it's non-aggregated and I want duplicate rows in the result set. SQL allowing duplicate rows is a departure from the underlying relational paradigm.
* Except for the special case when it's non-aggregated and I want duplicate rows in the result set. SQL allowing duplicate rows is a departure from the underlying relational paradigm.