Re: [PATCH] parser: optionally warn about missing AS for column and table aliases

05.09.2014 23:45, Marko Tiikkaja kirjoitti:
> On 2014-09-05 22:38, Oskari Saarenmaa wrote:
>> I wrote the attached patch to optionally emit warnings when column or
>> table
>> aliases are used without the AS keyword after errors caused by typos in
>> statements turning unintended things into aliases came up twice this
>> week.
>> First in a discussion with a colleague who was surprised by a 1 row
>> result
>> for the query 'SELECT COUNT(*) files' and again in the "pl/pgsql 2"
>> thread
>> as plpgsql currently doesn't throw an error if there are more result
>> columns
>> than output columns (SELECT a b INTO f1, f2).
>>
>> The patch is still missing documentation and it needs another patch to
>> modify all the statements in psql & co to use AS so you can use things
>> like
>> \d and tab-completion without triggering the warnings. I can implement
>> those changes if others think this patch makes sense.
>
> I think this is only problematic for column aliases. I wouldn't want to
> put these two to be put into the same category, as I always omit the AS
> keyword for tables aliases (and will continue to do so), but never omit
> it for column aliases.

I prefer using AS for both, but I can see the case for requiring AS in
table aliases being a lot weaker. Not emitting warnings for table
aliases would also reduce the changes required in psql & co as they seem
to be using aliases mostly (only?) for tables.

What'd be a good name for the GUC controlling this,
missing_column_as_warning?

/ Oskari