Re: PQexecParams, placeholders and variable lists of params

[Дмитрий Иванов <firstdismay@xxxxxxxxx>]

Hi

A function cannot have an undefined signature, but can accept an array of arguments:

CREATE OR REPLACE FUNCTION bpd.object_del_by_id_array(
object_array bigint[])
    RETURNS SETOF bpd.errarg_action
    LANGUAGE 'plpgsql'
    COST 100
    VOLATILE SECURITY DEFINER PARALLEL SAFE
    ROWS 1000
    SET search_path=bpd
AS $BODY$
DECLARE
    cfg_desc "bpd"."cfg_action"%ROWTYPE;
    action_entity RECORD;
           
    action_result RECORD;
    result "bpd"."errarg_action"%ROWTYPE;
BEGIN
SELECT * INTO cfg_desc FROM "bpd"."cfg_action" WHERE id = 'delete';

        FOR action_entity IN SELECT id, "name" FROM bpd.object WHERE id = ANY(object_array)
        LOOP
action_result = "bpd"."object_del"(action_entity.id);
result."err_id" = action_result.outresult;
result."errdesc" = action_result.outdesc;
result."entity_id" = 20;
result."entity_instance_id" = action_entity.id;
result."entity_instance_name" = action_entity.name;
result."action_id" = cfg_desc."actid";
result."action_desc" = cfg_desc.desc;
            RETURN NEXT result;
        END LOOP;
END;
$BODY$;

--

Regards, Dmitry!

вт, 23 нояб. 2021 г. в 16:37, <tomas@xxxxxxxxxx>:

Hi,

PQexecParams expects a query string with "$1", "$2"... placeholders,
which refer to as many params in the param list. This keeps SQL
injection at bay.

Is there a way to express "variable length" lists? IOW, if I want to do
a query like

  "SELECT * FROM customers WHERE id IN ($1, $2) AND name like $3;"

is there a way to do that without knowing beforehand how many values go
into the IN list?

It would be very welcome for you to rub my nose against the place in The
Fine Manual where I could have found that :-)

Thanks & cheers
 - tomás