query has no destination for result data i am facing this error - postgresql

Question

PostgreSQL 14
TABLE
CREATE TABLE IF NOT EXISTS settings.tbl_tmp
(
pk_sys_qr_settings_id bigint NOT NULL DEFAULT nextval('settings.tbl_tmp_pk_sys_qr_settings_id_seq'::regclass),
sin_product smallint DEFAULT 0,
vhr_key character varying(10) COLLATE pg_catalog."default" NOT NULL,
vhr_value character varying(250) COLLATE pg_catalog."default",
CONSTRAINT tbl_tmp_pkey PRIMARY KEY (pk_sys_qr_settings_id),
CONSTRAINT tbl_tmp_vhr_key_key UNIQUE (vhr_key)
)
--FUNCTION 1 - CALL FROM fn_test
CREATE OR REPLACE FUNCTION fn_test1(sinProduct SMALLINT,
vhrKey VARCHAR(10),
vhrValue VARCHAR(250))
RETURNS VOID AS $$
BEGIN
INSERT INTO settings.tbl_tmp
(sin_product, vhr_key, vhr_value)
VALUES
(sinProduct, vhrKey, vhrValue);
END;
$$ LANGUAGE plpgsql;
FUNCTION 2
CREATE OR REPLACE FUNCTION fn_test(sinProduct SMALLINT,
vhrKey VARCHAR(10),
vhrValue VARCHAR(250))
RETURNS VOID AS $$
DECLARE
a SMALLINT;
BEGIN
BEGIN
SELECT * FROM fn_test1(1::SMALLINT, 'Anil-5'::VARCHAR(10), 'KV-5'::VARCHAR(250));
INSERT INTO settings.tbl_tmp
(sin_product, vhr_key, vhr_value)
VALUES
(sinProduct, vhrKey, vhrValue);
END;
END;
$$ LANGUAGE plpgsql;
--ERROR
ERROR: query has no destination for result data
HINT: If you want to discard the results of a SELECT, use PERFORM instead.
CONTEXT: PL/pgSQL function fn_test(smallint,character varying,character varying) line 7 at SQL statement
SQL state: 42601

Answer 1

Quote from the manual
Sometimes it is useful to evaluate an expression or SELECT query but discard the result, for example when calling a function that has side-effects but no useful result value. To do this in PL/pgSQL, use the PERFORM statement:
As the called function doesn't return anything to begin with, it's safe to use perform.
So use:
perform fn_test1(1::SMALLINT, 'Anil-5'::VARCHAR(10), 'KV-5'::VARCHAR(250));
Instead of select * from fn_test(..)
As you are using Postgres 14, you could also use a procedure in both cases, as you don't want to return a result.