Re: expression evaluation with expected datatypes

Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> When I worked on parametrised DO statement, I had to solve following issue:

DO currently is a utility command, not a query. Do you mean to change
that?

Also, did you think about a lambda construct, which is basically
allowing functions to be defined inline in a query?

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>;

Other WITH extensions we can think about include support for DCL as
asked by David Fetter in the past already, and support for variables too
(a kind of per-query SET LOCAL).

I don't see how adding parameters and return values to utility commands
is going to be easier than adding a "lambda" facility.

Regards,
--
Dimitri Fontaine
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support