Postgresql [42P01] ERROR: relation does not exist during trigger function - postgresql

Question

I am trying to write a trigger that stores previous versions of a row in a table named audit_tablename given a table named tablename.
Here is the the code...
CREATE OR REPLACE FUNCTION process_ui_audit()
RETURNS TRIGGER AS
$$
DECLARE
audit_table_name text := TG_TABLE_SCHEMA || '.audit_' || TG_TABLE_NAME;
audit_table_schema text := TG_TABLE_SCHEMA;
BEGIN
IF (TG_OP = 'UPDATE')
THEN
EXECUTE FORMAT('INSERT INTO %1$I SELECT NEXTVAL(''$1.hibernate_sequence''),now(), user, ($1).*',
audit_table_name, audit_table_schema)
USING OLD;
NEW.version = OLD.version + 1;
RETURN NEW;
ELSIF (TG_OP = 'INSERT')
THEN
NEW.version = 1;
RETURN NEW;
END IF;
END;
When I try to update a row the trigger runs and I get errors like this....
[42P01] ERROR: relation "webapp.audit_portal_user" does not exist
Where: PL/pgSQL function webapp.process_ui_audit() line 13 at EXECUTE
I am wonderin am I formatting table names incorrectly or something? The table name webapp.audit_portal_user definetly exists.

Answer 1

It works without specifying schema name.
Here is a simplified example:
create table portal_user(
uid int,
uname text
);
CREATE TABLE
create table audit_portal_user(
uid int,
uname text,
who text,
what text,
ts timestamp
);
CREATE TABLE
create or replace function process_ui_audit()
returns trigger as
$$
declare
audit_table_name text := 'audit_' || tg_table_name;
begin
if (tg_op = 'UPDATE')
then
execute format('insert into %I values($1.*, user, %L, now())',
audit_table_name, 'UPDATE') using new;
return null;
end if;
end;
$$
language plpgsql;
CREATE FUNCTION
create trigger audit
after update on portal_user
for each row
execute function process_ui_audit();
CREATE TRIGGER
insert into portal_user values(12, 'titi');
INSERT 0 1
select * from portal_user;
uid | uname
-----+-------
12 | titi
(1 row)
update portal_user set uname='toto' where uid=12;
UPDATE 1
select * from portal_user;
uid | uname
-----+-------
12 | toto
(1 row)
select * from audit_portal_user;
uid | uname | who | what | ts
-----+-------+----------+--------+----------------------------
12 | toto | postgres | UPDATE | 2020-06-01 10:20:36.549257
(1 row)