PLSQL - Check if an object exists in a table of objects - type has no map - oracle

Question

I have a procedure that has got this variables of type table of objects:
lsa_final_filter_ports t_modifylink_multicolumnlist;
lsa_initial_filter_ports t_modifylink_multicolumnlist;
Definition of t_modifylink_multicolumnlist is:
CREATE OR REPLACE TYPE "T_MODIFYLINK_MULTICOLUMNLIST" IS TABLE OF o_modifylink_multicolumnlist;
TYPE o_modifylink_multicolumnlist AS OBJECT(some properties);
lsa_final_filter_ports variable is populated like this
SELECT b.name INTO ls_bandwidth_name FROM bandwidth b
WHERE b.bandwidthid = lna_compatible_port_bw(i);
SELECT CAST(MULTISET(SELECT *
FROM TABLE(piosa_all_ports)
WHERE ITEMNAME4 = ls_bandwidth_name)
AS t_modifylink_multicolumnlist)
INTO lsa_final_filter_ports
FROM dual;
Where piosa_all_ports is I/O parameter having same type t_modifylink_multicolumnlist
Second parameter is initialized at the beginig of procedure with a second I/O parameter that the procedure has
lsa_initial_filter_ports := piosa_filtered_ports;
What I want to achieve is to check if an object from lsa_final_filter_ports exists in lsa_initial_filter_ports and if so then skip adding that object in lsa_initial_filter_ports which will be an output parameter used by the outside calling procedure.
What I've tried is iterating through lsa_final_filter_ports objects and checking if that object already exists like this:
FOR i in 1..lsa_final_filter_ports.COUNT LOOP
IF lsa_final_filter_ports(i) MEMBER OF lsa_initial_filter_ports THEN
CONTINUE;
END IF;
lsa_initial_filter_ports.EXTEND();
lsa_initial_filter_ports(lsa_initial_filter_ports.COUNT) := lsa_final_filter_ports(i);
END LOOP;
But with this code I'm getting the following error:
Error: PLS-00801: internal error [*** ASSERT at file pdw4.c, line
2181; Type 0x0x7f991127aef8 has no MAP method.;
NR_WIZARDVALIDATIONS__CUSTOMISATIONS__B__166833[33]
I'm not sure if this kind of comparation can be made, maybe someone can clarify this.
Thank you

Answer 1

Unfortunately, if you have objects in PlSql, which only exist in RAM (that means those, that are NOT stored persistently in a table), assigning them to another variables always causes a (deep) copy of the origin object.
(which is really a problem, if you often assign objects with nested objects to working-variables and back to the collection ...)
Therefore, you´ll never will be able to compare two (copies) of the same object on object-pointer level.
Only thing you can do, is comparing some unique attributes of the objects.
Let´s say, you´ll have an ID in your piosa_all_ports, then you might modify your loop above with the comparison in something similar to this:
v_exists integer;
FOR i in 1..lsa_final_filter_ports.COUNT LOOP
select nvl(max(1),0)
from table(lsa_initial_filter_ports) x
where x.id = lsa_final_filter_ports(i).id;
if (v_exists = 0) then
lsa_initial_filter_ports.EXTEND();
lsa_initial_filter_ports(lsa_initial_filter_ports.COUNT) := lsa_final_filter_ports(i);
end if;
END LOOP;
(rem.: i know, that switching PlSql- and SQL-Context in sample above is time-consuming, but otherwise, you have to write a function that tests the existance of an ID by iterating the whole list)