Sunday, August 17, 2008

Re: [HACKERS] proposal sql: labeled function params

Hannu

it's not possible in plpgsql, because we are not able iterate via record.

Pavel

2008/8/17 Hannu Krosing <hannu@2ndquadrant.com>:
> On Sun, 2008-08-17 at 11:08 -0400, Tom Lane wrote:
>> Hannu Krosing <hannu@2ndQuadrant.com> writes:
>> > Actually the most "natural" syntax to me is just f(name=value) similar
>> > to how UPDATE does it. It has the added benefit of _not_ forcing us to
>> > make a operator reserved (AFAIK "=" can't be used to define new ops)
>>
>> *What* are you thinking?
>
> I think that we could achieve what Pavel was after by allowing one to
> define something similar to keyword arguments in python.
>
> maybe allow input RECORD type, which is instantiated at call time by
> giving extra arguments to function call:
>
> CREATE FUNCTION f_kw(r record) ....
>
> and then if you call it like this:
>
> SELECT ... f_kw(name='bob', age=7::int)
>
> then function gets as its input a record
> which can be accessed in pl/pgsql like
>
> r.name r.age
>
> and if terseness is really appreciated then the it could also be called
> like this
>
> SELECT ... f_kw(name, age) from people where name='bob';
>
> which is rewritten to
>
> SELECT ... f_kw(name=name, age=age) from people where name='bob';
>
>
> not sure if we should allow defining SETOF RECORD and then enable
> calling it with
>
> SELECT *
> FROM f_kw(
> VALUES(name='bob', age=7::int),
> VALUES(name='bill', age=42::int
> );
>
> or somesuch
>
> ------------------
> Hannu
>
>
>

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