Re: [HACKERS] proposal: PLpgSQL parallel assignemnt

2017-06-02 10:15 GMT+02:00 Pavel Stehule <pavel.stehule@gmail.com>:

2017-06-02 10:06 GMT+02:00 Craig Ringer <craig@2ndquadrant.com>:

On 2 June 2017 at 15:51, Pavel Stehule <pavel.stehule@gmail.com> wrote:

> a, b := fx();
>
> Comments, notes, ideas?

I'd be pretty happy to have

(a, b) = (x, y);
(a, b) = f(x);

which is SQL-esque.

This is not too far to my proposal - and it is fully adequate alternative. 

The ANSI form is related to SET or UPDATE commands - so in this case I see classic languages style https://en.wikipedia.org/wiki/Assignment_(computer_science) better. The assign statement in PLpgSQL is not related to embedded SQL. If we introduce SQL syntax and SET commands for schema variables then ( ) syntax is perfect, but for := PLpgSQL I am not sure

It is maybe strange, but

SET (a,b) =  (SELECT a,b FROM foo)

a, b := fx()

are sentences from two independent worlds and different syntax can be correct (depends how much we would to integrate procedural and SQL worlds .. 100% T-SQL, 80% SQL/PSM, ..20% PLpgSQL or 5%PL/SQL)

Regards

Pavel

 

 

But what, if anything, does Ada do?

What I know, no, Ada has not this statement - but the design of OUT parameters in Ada absolutely different than PostgreSQL - so in this case we cannot to use Ada language as our base :(

Regards

Pavel

 

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