Re: Example 42.4. A PL/pgSQL Trigger Function for Auditing
Dne po 16. 12. 2019 20:28 uživatel Tom Lane napsal: > Pavel Stehule writes: > > po 16. 12. 2019 v 12:12 odesílatel PG Doc comments form < > > nore...@postgresql.org> napsal: > >> I'm wondering if it would be worthwhile to put a totally generic > auditing > >> function into the documentation e.g. > >> [ snip ] > > > Just few points to this code > > I agree this code could have better style, but maybe that is just more > evidence that a well-written example would be helpful? > +1 there is not too much examples for trigger parameters. > regards, tom lane >
Re: Example 42.4. A PL/pgSQL Trigger Function for Auditing
> On 16 Dec 2019, at 20:27, Tom Lane wrote: > > .. maybe that is just more > evidence that a well-written example would be helpful? I think thats the key takeaway here. +1 on the gist of the suggestion that started this thread. cheers ./daniel
Re: Example 42.4. A PL/pgSQL Trigger Function for Auditing
Pavel Stehule writes: > po 16. 12. 2019 v 12:12 odesílatel PG Doc comments form < > nore...@postgresql.org> napsal: >> I'm wondering if it would be worthwhile to put a totally generic auditing >> function into the documentation e.g. >> [ snip ] > Just few points to this code I agree this code could have better style, but maybe that is just more evidence that a well-written example would be helpful? regards, tom lane
Re: Example 42.4. A PL/pgSQL Trigger Function for Auditing
po 16. 12. 2019 v 12:12 odesílatel PG Doc comments form <
nore...@postgresql.org> napsal:
> The following documentation comment has been logged on the website:
>
> Page: https://www.postgresql.org/docs/12/plpgsql-trigger.html
> Description:
>
> I'm wondering if it would be worthwhile to put a totally generic auditing
> function into the documentation e.g.
>
> CREATE OR REPLACE FUNCTION zz_audit_() RETURNS TRIGGER AS $nothing$
>
> -- This function is intended to be used by a delete/insert/update trigger
> for any table.
> -- It relies on the existence of a table named zz_audit_XXX (where XXX is
> the table being audited) that contains the
> -- same columns as the table XXX except that two additional columns must
> exist prior to the columns from XXX
> --operation character(1) NOT NULL,
> --tstamptimestamp with time zone NOT NULL,
> --... remaining columns per table XXX
>
> DECLARE audit_table_name NAME := CONCAT('zz_audit_', TG_TABLE_NAME);
> BEGIN
>
> IF (TG_OP = 'DELETE') THEN
> EXECUTE 'INSERT INTO ' || audit_table_name || ' SELECT ''D'',
> now(), ' || ' $1.*' USING OLD;
> ELSIF (TG_OP = 'UPDATE') THEN
> EXECUTE 'INSERT INTO ' || audit_table_name || '
> SELECT ''U'', now(), ' ||
> ' $1.*' USING NEW;
> ELSIF (TG_OP = 'INSERT') THEN
> EXECUTE 'INSERT INTO ' || audit_table_name || '
> SELECT ''I'', now(), ' ||
> ' $1.*' USING NEW;
> END IF;
>
> RETURN NULL; -- result is ignored since this is an AFTER trigger
> END;
> $nothing$ LANGUAGE plpgsql;
>
Just few points to this code
1. bad, useless brackets in IF .. ELSIF expressions - plpgsql is not C or
Java
2. unescaped identifiers in dynamic SQL - EXECUTE
3. there is not reason for INSERT SELECT.
Regards
Pavel
Re: Example 42.4. A PL/pgSQL Trigger Function for Auditing
The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/12/plpgsql-trigger.html
Description:
I'm wondering if it would be worthwhile to put a totally generic auditing
function into the documentation e.g.
CREATE OR REPLACE FUNCTION zz_audit_() RETURNS TRIGGER AS $nothing$
-- This function is intended to be used by a delete/insert/update trigger
for any table.
-- It relies on the existence of a table named zz_audit_XXX (where XXX is
the table being audited) that contains the
-- same columns as the table XXX except that two additional columns must
exist prior to the columns from XXX
--operation character(1) NOT NULL,
--tstamptimestamp with time zone NOT NULL,
--... remaining columns per table XXX
DECLARE audit_table_name NAME := CONCAT('zz_audit_', TG_TABLE_NAME);
BEGIN
IF (TG_OP = 'DELETE') THEN
EXECUTE 'INSERT INTO ' || audit_table_name || ' SELECT ''D'',
now(), ' || ' $1.*' USING OLD;
ELSIF (TG_OP = 'UPDATE') THEN
EXECUTE 'INSERT INTO ' || audit_table_name || ' SELECT
''U'', now(), ' ||
' $1.*' USING NEW;
ELSIF (TG_OP = 'INSERT') THEN
EXECUTE 'INSERT INTO ' || audit_table_name || ' SELECT
''I'', now(), ' ||
' $1.*' USING NEW;
END IF;
RETURN NULL; -- result is ignored since this is an AFTER trigger
END;
$nothing$ LANGUAGE plpgsql;
