insertion in a table of objects with nested table in oracle

Question

I have a problem inserting in a nested table in oracle

These are the relevant types and tables;

create type movies_type as Table of ref movie_type;

create type actor_type under person_type

(

starring movies_type

) Final;

create table actor of actor_type

NESTED TABLE starring STORE AS starring_nt;

this is how i tried to insert

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YY'),TO_DATE('27/12/2016', 'DD/MM/YY'),'USA', movies_type(select ref(m) from movie m where movie_id in (7, 8, 9))));

this doesn't work, it gives

SQL Error: ORA-00936: missing expression

which isn't very helpful.

i also tried nesting the select statement in parenthesis because i thought it might have been a syntax error

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YY'),TO_DATE('27/12/2016', 'DD/MM/YY'),'USA', movies_type((select ref(m) from movie m where movie_id in (7, 8, 9)))));

but it said

SQL ERROR ORA-01427: single-row subquery returns more than one row

so i changed it to this

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YY'),TO_DATE('27/12/2016', 'DD/MM/YY'),'USA', movies_type((select ref(m) from movie m where movie_id=7))));

which worked but it isn't what i want since it doesn't allow me to have multiple values in

movies_type

i don't understand what the problem is exactly and the errors messages aren't helpful

why does it say missing expression?

and why in the second case it gives single-row sub-query returns more than one row?

thank you very much.

Update: here is the type movie_type and table movie:

create type movie_type as Object
(
  MOVIE_ID NUMBER(15),
  TITLE VARCHAR(50) ,
  GENRE  VARCHAR(30),
  RELEASE_DATE DATE,
  RUNNING_TIME NUMBER,
  BUDGET NUMBER
) Final;

table creation:

create table MOVIE of movie_type;

ALTER TABLE MOVIE
  ADD CONSTRAINT PK_MOVIE_ID PRIMARY KEY (MOVIE_ID);

ALTER TABLE MOVIE modify TITLE not null;

relevant insertions in movie:

INSERT INTO MOVIE (MOVIE_ID, TITLE, GENDER, RELEASE_DATE, RUNNING_TIME, BUDGET) VALUES (7,'Star Wars','epic space opera',TO_DATE('25/05/1977', 'DD/MM/YY'),121,11000000);

INSERT INTO MOVIE (MOVIE_ID, TITLE, GENDER, RELEASE_DATE, RUNNING_TIME, BUDGET) VALUES (8,'The Empire Strikes Back','epic space opera',TO_DATE('17/05/1980', 'DD/MM/YY'),124,18000000);

INSERT INTO MOVIE (MOVIE_ID, TITLE, GENDER, RELEASE_DATE, RUNNING_TIME, BUDGET) VALUES (9,'Return of the Jedi','epic space opera',TO_DATE('25/05/1983', 'DD/MM/YY'),132,32500000);

Answer 1

movies_type() is the CONSTRUCTOR FUNCTION for movies_type

It requires 1 or more instances of movie_type. Each one separated by a comma.

You're only making a single instance in your SQL.

The magic incantation you seek is:

Cast(multiset( select... ) as movies_type)

How It Works

movies_type is a Nested Table type.

You can Construct an NT of cardinality 1 by specifying a single Scalar SQL statement. (this is what you have in your 3rd attempt)

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YYYY'),TO_DATE('27/12/2016', 'DD/MM/YYYY'),'USA'
    ,movies_type(
        (select ref(m) from movie m where movie_id = 7) -- single element
    )
));

Additionally, you can construct an NT of cardinality n by specifying n elements. In this example, I supply 3x Scalar SQL statements.

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YYYY'),TO_DATE('27/12/2016', 'DD/MM/YYYY'),'USA'
    ,movies_type(
        (select ref(m) from movie m where movie_id = 7), -- element 1
        (select ref(m) from movie m where movie_id = 8), -- element 2
        (select ref(m) from movie m where movie_id = 9)  -- element 3
    )
));

But, that's not what you want.

In order to turn a SELECT statement into an Array of elements, you need to use cast(multiset() as data_type) like so:

insert into actor values
(actor_type(29,'Carrie','Fisher',TO_DATE('21/10/1956', 'DD/MM/YYYY'),TO_DATE('27/12/2016', 'DD/MM/YYYY'),'USA'
    ,cast(multiset(
                    select ref(m) from movie m where movie_id in (7,8,9)
                 ) as movies_type)
));