Re: How to return argument data type from sql function

Hi!
Making separate functions for text and bpchar works for me.

regression=# select pg_typeof(torus(f1)) from char_tbl; pg_typeof 
----------- character

I tried

create or replace FUNCTION torus(eevarus bpchar) returns bpchar immutable AS $f$
select translate( $1, U&'\00f8\00e9', U&'\0451\0439' );
$f$ LANGUAGE SQL ;

create temp table test (
charcol char(10) );
insert into test values ('test');
select torus(charcol)
FROM Test

but it still returns result without trailing spaces. So it is not working.

Another possibility is to have just one function declared
to take and return anyelement.  You'd get failures at
execution if the actual argument type isn't coercible
to and from text (since translate() deals in text) but
that might be fine.

I tried

create or replace FUNCTION torus(eevarus anylement ) returns anylement immutable AS $f$
select translate( $1, U&'\00f8\00e9', U&'\0451\0439' );
$f$ LANGUAGE SQL ;

but got error

type anyelement does not exists.

Finally I tried

create or replace FUNCTION torus(eevarus text ) returns text immutable AS $f$
select translate( $1, U&'\00f8\00e9', U&'\0451\0439' );
$f$ LANGUAGE SQL ;

create or replace function public.ColWidth(p_namespace text, p_table text, p_field text)
    returns int as $f$
select atttypmod-4 from pg_namespace n, pg_class c, pg_attribute a
         where n.nspname = p_namespace and
             c.relnamespace = n.oid and
             c.relname = p_table and
             a.attrelid = c.oid and
             a.attname = p_field;
$f$ LANGUAGE SQL ;

create table public.test ( charcol char(10) );
insert into test values ('test');
select rpad ( torus(charcol),  colwidth('public', 'test', 'charcol') )
FROM Test

as Adrian Klaver recommends in

https://stackoverflow.com/questions/74061290/how-to-return-argument-datatype-from-sql-function#comment130780708_74061290

at this worked. In this best solution?

How to remove p_namespace  parameter from colwidth()? ColWidth() should return column width in first search_path table just like  select ... from test finds table test.

Andrus.