26.11.2014 18:52, Mark Rotteveel wrote:
>
> I initially had a similar implementation (slightly more complex), but I
> decided to extend select_expr so the new production reads more like the
> production in the SQL standard:
>
> Compare parse.y:
> select_expr
>       : ...
>       | with_clause select_expr_body order_clause result_offset_clause
> fetch_first_clause
>
> with SQL:2011:
> <query expression> ::=
> [<with clause>] <query expression body>
> [<order by clause>] [<result offset clause>] [<fetch first clause>]
>
> Both will work, but I like the elegance of my current solution: it makes
> it easier to compare syntax with the SQL spec*. However your suggestion
> removes some repetition, and would make it easier to address your second
> point.
>
> What do you want me to do?

Keep your current solution.

>> 3) New reserved words (OFFSET and ROW) should be added to the
>> keyword_or_column rule to simplify migration. That said, I'm wondering
>> why ROWS wasn't added there too in v2.0. Probably my oversight.
>
> What does this do? Does this allow a keyword to be used as a column name
> without quoting it?

It allows to rename a column having unlucky (reserved) name.

> I was wondering: Do you agree with my introduction and use of
> simple_value_spec with result_offset_clause and fetch_first_clause? This
> restricts the values to literals (constants), parameters or variables as
> in the standard, but it takes away some flexibility (like allowing
> expressions, column references etc) as is currently possible with ROWS.

Honestly, I don't know. Your solution should cover 99% of all use cases 
but there may still be some weird misuses. Perhaps we may start with 
standard-compliant "simple_value_spec" and extend it to full-featured 
"value" once someone sends a bugreport to the tracker ;-)


Dmitry


------------------------------------------------------------------------------
Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
from Actuate! Instantly Supercharge Your Business Reports and Dashboards
with Interactivity, Sharing, Native Excel Exports, App Integration & more
Get technology previously reserved for billion-dollar corporations, FREE
http://pubads.g.doubleclick.net/gampad/clk?id=157005751&iu=/4140/ostg.clktrk
Firebird-Devel mailing list, web interface at 
https://lists.sourceforge.net/lists/listinfo/firebird-devel

Reply via email to