Oracle triggers enable primary key auto-increment

drop table book; --CREATE TABLE BookId varchar2 (4) primary key, name VARCHAR2 ( -)         ); --Creating a sequence Create sequence book_seq start with1Increment by1; --creating a trigger Create or replace trigger Book_trigger before insert on book forEach row beginSelectBook_seq.nextval into:New. bookId fromdual;   End; --Add data insert into book (name) VALUES ('cc'); Insert into book (name) VALUES ('DD');   Commit Query data:Select* fromBook

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SELECT * from user_objects UBS where UBS. Object_type= ' SEQUENCE ';