Re: operator is only a shell - Error

Sorry Adrian, my bad. I'd mentioned "deposit_sub_no='1'" by mistake, actually it was "deposit_sub_no=cast(1 as varchar)".  This was throwing error "SQL Error [42883]: ERROR: operator does not exist: numeric = character varying  Hint: No operator matches the given name and argument types. You might need to add explicit type casts.  Position: 19".  Then realized that "numeric=text" works but "numeric=varchar" does not.  I could resolve the problem by creating the following function and operator by commenting "CUMMUTATOR" and "NEGATOR".  Also the error "operator is only a shell" also vanished.  I'm just sharing the script for your reference.  Thank you very much for your valuable support.

CREATE OR REPLACE FUNCTION public.num_eq_varchar(
    numeric,
    varchar)
    RETURNS boolean
AS 'select case when $2 ~ ''^[0-9\.]+$'' then $1 operator(pg_catalog.=) cast($2 as numeric) else $1::varchar = $2 end;'
LANGUAGE SQL IMMUTABLE;

-- Operator: =;

-- DROP OPERATOR IF EXISTS public.= (numeric , varchar);

CREATE OPERATOR public.= (
    FUNCTION = num_eq_varchar,
    LEFTARG = numeric,
    RIGHTARG = varchar,
--     COMMUTATOR = =,
--     NEGATOR = <>,
    RESTRICT = eqsel,
    JOIN = eqjoinsel,
    HASHES, MERGES
);

On 3/18/24 00:05, Rajesh S wrote:

Thank you for your response.  Actually, I was trying to address the following query.

select LIEN_AC_NO from deposit_lien where deposit_no='0002114029832' and deposit_sub_no='1' and unlien_dt is null and unlien_remarks is null;

In the above query "deposit_sub_no" column is "numeric" type and passing '1' (as varchar).  To address this I'd created the function and operator as I'd mentioned in the earlier mail.  Even the following query throws error after creating the function and operator.

select * from deposit_lien where deposit_no='0002114029832';

ERROR: operator is only a shell: character varying = numeric LINE 1: select * from deposit_lien where deposit_no='0002114029832' ^ SQL state: 42883 Character: 44

In the above query "deposit_no" column is having "varchar" data type.  But before creating the function and operator it was working fine.  Tried dropping the same, even though the same error.  How to proceed now?

Not clear to me what the problem is you are trying to solve?

On a stock Postgres install:

select 1::numeric = '1';
 ?column?
----------
 t

select '0002114029832'::varchar = '0002114029832';
 ?column?
----------
 t

Thanks,

Rajesh S

On 15-03-2024 19:10, Greg Sabino Mullane wrote:

On Fri, Mar 15, 2024 at 6:26 AM Rajesh S <rajesh.s@fincuro.com> wrote:

    I wanted to implement a new "=" (equal) operator with LEFTARG as
    numeric and RIGHTARG as varchar.  But after creating the function
    and operator, psql shows the error "operator is only a shell:
    character varying = numeric

Your operator has numeric on the left and varchar on the right. But your query is doing numeric on the RIGHT. Probably want to make a matching one to cover both cases.

Cheers,
Greg