Re: [SPAM] Re: Partial table duplication via triggger

On 22/02/24 17:49, Erik Wienhold wrote:
> On 2024-02-22 15:14 +0100, Moreno Andreo wrote:
>> suppose I have 2 tables
>> [snip]
>> What am I missing?
> The parameters you pass in with USING have to be referenced as $1, $2,
> and so on.  For example:
>
>     DECLARE
>         fieldlist text := (
>             SELECT string_agg(quote_ident(column_name), ', ')
>             FROM information_schema.columns
>             WHERE table_name = TG_TABLE_NAME AND column_name <> 'id'
>         );
>         oldfieldlist text := (
>             SELECT string_agg('$1.' || quote_ident(column_name), ', ')
>             FROM information_schema.columns
>             WHERE table_name = TG_TABLE_NAME AND column_name <> 'id'
>         );
>     BEGIN
>         EXECUTE '
>             INSERT INTO t2 (id, master_id, op_ts, ' || fieldlist || ')
>             VALUES (gen_random_uuid(), $1.id, now(), ' || oldfieldlist || ')
>         ' USING OLD;
>         RETURN NULL;
>     END;
>
> Also make sure to use quote_ident() when constructing statements that
> way to avoid SQL injections via column names in this case.  Or use
> format() with placeholder %I, although it's not simpler when you need to
> construct that variable list of identifiers.
>
Erik,
It worked perfectly!
I had not clear in mind how to use $1, $2, etc, with using; after your 
reply I had a closer look at the docs and now it's clearer to me.

Many thanks,
Moreno.