Variant (Untyped) parameter for function/procedure

On 6/5/24 01:34, Durumdara wrote:

Dear Members!

As I experienced, the functions/procedures extremely depend on
parameters (very typed).
So if I have to restructure the input parameters, I can't modify the
function, because I have to recreate the dependents too.
For example:
I have a type. If I pass this type to a function, I can't change the
structure of the type without dropping and recreating the function.

create type blahtype as (a int, b bool);
create function blahcheck (input blahtype) ...

If I have many dependent functions this causes that I have to drop
(recreate) everything - just for an extra parameter. And sometimes this
extra parameter doesn't change 10 functions, only one. But I have to
recreate them all (without changing the body).

Is there any way to use a Variant parameter?

You mean like:

https://www.postgresql.org/docs/current/extend-type-system.html#EXTEND-TYPES-POLYMORPHIC

Examples here:

https://www.postgresql.org/docs/current/plpgsql-declarations.html#PLPGSQL-DECLARATION-PARAMETERS

Starting at:

"... When the return type of a PL/pgSQL function is declared as a
polymorphic type ..."

Or there is VARIADIC:

https://www.postgresql.org/docs/current/xfunc-sql.html#XFUNC-SQL-VARIADIC-FUNCTIONS

Like this:

create procedure test(IN Input Record, OUT Output Record)
...
    Time = Input.Time::timestamp;
...

    Output = SomeHowMakeItTyped;

    Output.Result = 1;

...

Caller:

...
for r_in as select  id, name from blah into
...
     test(r_in, r_out);
     if r_out.result <> 0 then ...

Or:

create procedure test(IN Inputs Records, OUT Output Record)
...
        for Input in Inputs:
        Time = Input.Time::timestamp;
...
    Output.Result = 1;
...

Or is it impossible, because of the PGSQL's philosophy (very typed)?

If it is not possible then I have one way I think.
It is a JSON data type for inputs and outputs.

Is that right?

Thanks for your any help, info!

Best regards
dd

--
Adrian Klaver
adrian.klaver@aklaver.com