Adding Constraints to VARRAY UDT inside a Table in PLSQL - sql

Question

I'm stuck figuring out how to add some constraints to the attributes of my UDTs.
Here's my situation. I've got a UDT that represents the daily number of hours an employee should work (forgive me for using Italian names).
CREATE OR REPLACE TYPE TURNO_GIORNALIERO AS OBJECT(
GIORNO VARCHAR(15),
ORA_INIZIO DATE,
NUMERO_ORE NUMBER,
MEMBER FUNCTION getOreLavoro RETURN NUMBER
);
Then I defined new Type as a VARRAY(5) of TURNO_GIORNALIERO, named TURNI_SETTIMANALI (that is a Varray containing the number of hours an employee should work for each day of the week).
CREATE OR REPLACE TYPE TURNI_SETTIMANALI AS VARRAY(5) OF TURNO_GIORNALIERO;
In the end, I've created the table that contains TURNI_SETTIMANALI.
CREATE TABLE TURNO_LAVORO(
ID_TURNO CHAR(9) PRIMARY KEY,
TURNO TURNI_SETTIMANALI NOT NULL,
);
What I want to do is to add a constraint to the table TURNO_LAVORO in order to check if NUMERO_ORE (defined in TURNO GIORNALIERO) is greater than 5.
Could someone please help me? I've tried several solutions but nothing worked.

Answer 1

I doubt it is possible in check constraint. Documentation says:
Conditions of check constraints cannot contain the following
constructs:
Calls to user-defined functions
Nested table columns or attributes
You could use trigger however. Test types and table:
create or replace type daily_cycle
as object(day varchar(15), hour_start date, hour_count number);
create or replace type week_cycle
as varray(5) of daily_cycle;
create table test(id int, shift week_cycle);
Trigger:
create or replace trigger hour_check before insert on test for each row
begin
for i in 1..:new.shift.count() loop
if :new.shift(i).hour_count < 5 then
raise_application_error(-20001,'hours less than 5');
end if;
end loop;
end;
First insert works, second no:
insert into test values (1,
week_cycle(daily_cycle('a', date '2017-12-01', 5),
daily_cycle('b', date '2017-12-02', 8) ) );
insert into test values (2,
week_cycle(daily_cycle('a', date '2017-12-03', 3),
daily_cycle('b', date '2017-12-04', 12),
daily_cycle('b', date '2017-12-05', 7) ) );