Re: expression evaluation with expected datatypes

2012/7/10 Tom Lane <tgl@sss.pgh.pa.us>:
> Dimitri Fontaine <dimitri@2ndQuadrant.fr> writes:
>> We could imagine several syntax to show up the idea, common keywords
>> here include LAMBDA, FLET or LABELS, but I think that expanding WITH
>> would be preferable for us.
>
>>   WITH FUNCTION foo(param list) returns rettype language foo AS (
>>     definition here
>>   )
>>   <query using foo() here>;
>
> I like this idea.  This gets rid of both the "how to pass parameters"
> and the "how to return results" issues that exist with DO, as well as
> assorted implementation problems that you hinted at by asking whether
> DO would still be a utility command.

what is use case for this statement?

Regards

Pavel

>
> In the syntax-bikeshedding department, we'd still need the function body
> to be a string literal, and I think we'd want the ability to add
> options such as IMMUTABLE/VOLATILE.  So I'd be inclined to move all
> these options inside the parentheses that the WITH syntax dictates.
> Perhaps
>
> WITH FUNCTION foo(paramlist) AS (
>         returns int
>         as $$ ... $$
>         language plpgsql
>         ... other CREATE FUNCTION options as needed ...
> )
> query here ...
>
>                         regards, tom lane