Oracle 18c

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

CREATE TABLE Books 
(
    Id int generated by default on null as identity,
    Title VARCHAR(50) NOT NULL,
    PRIMARY KEY(Id)
);
INSERT INTO Books (Id, Title)
VALUES
(3, 'The Catcher in the Rye');
1 rows affected

begin
INSERT INTO Books (Title) VALUES ('Nine Stories');
INSERT INTO Books (Title) VALUES ('The Great Gatsby');
INSERT INTO Books (Title) VALUES ('Tender id the Night');
INSERT INTO Books (Title) VALUES ('Pride and Prejudice');
INSERT INTO Books (Title) VALUES ('Professional ASP.NET 4.5 in C# and VB');
end;
/
ORA-00001: unique constraint (FIDDLE_VLNPJXSRPMFLLJKYKEJH.SYS_C0080297) violated
ORA-06512: at line 4

select* from Books;


ID
TITLE


3
The Catcher in the Rye