Geoff Worboys wrote:

>>A glance at the standard suggests that X AS Y in the select
>>list is called <derived column> AS <column name>. The
>>restrictions on the use of a <derived column> appear to be:
> ...
>
> It seems to me that these rules are talking about the derived
> column rather than the alias.

What we're calling an alias is called a "column name" in the standard.
The standards does include some restrictions on the use of column names,
but the only relevant ones I saw were those related to derived columns.
By inference, the standard appears to allow what we're calling aliases
in any part of a query expression.

Regards,


Ann