Oracle Database primary key auto-increment SQL

Oracle Database primary key auto-increment SQL

We all know that in MySQL, it is very easy to implement automatic increment of primary keys. you only need to add auto_increment after the primary key definition, but this is not the case in Oracle. It takes several steps to complete 1. create table account book (account INTEGER not null, user CHAR (20) not null, owner name CHAR (20) not null, address CHAR (200) not null, carrier CHAR (20) not null, DATE not null, constraint PK _ account primary key (account number); 2. CREATE a sequence SEQUENCE: CREATE sequence book_Sequence increment by 1 -- add a few start with 1 each time -- count NOMAXVALUE from 1 -- do not set the maximum value NOCYCLE; -- always accumulate, do not loop 3. CREATE a TRIGGER: create trigger book_increase BEFOREinsert ON account book for each ROWbeginselect BOOK_SEQUENCE.nextval into: New. user number from dual; end; this way, you can automatically increase the number when the primary key is null when the user table is inserted. it should be emphasized that it is very troublesome for some beginners to name them in Chinese .. but sequence must be in English ..