Datatype creation in SQL for Oracle

Question

Can i create my own datatype in SQL to use on an oracle database?

i tried creating an array or varchar2 : enter image description here to be able to create a table with a column with "genre_list" datatype : enter image description here

but when i tried to run this in sql developer i encountered this error message : enter image description here

Answer 1

Create the data type:

CREATE TYPE genre_list IS TABLE OF VARCHAR2(20);

Then create the table with a nested table:

CREATE TABLE book (
  id     NUMBER,
  isbn   VARCHAR2(20),
  genres genre_list
) NESTED TABLE genres STORE AS book__genres;