各数据库ID设置自增方法

Oracle，创建序列->创建触发器
yss_test_seq ehr
-- Create sequence
create sequence yss_test_seq
minvalue 1
start with 1
increment by 1
order;

create or replace trigger yss_test_trg
before insert on YSS_TEST
for each row  
begin  
select yss_test_seq.nextval into:New.id from dual;

end yss_test_trg;

SqlServer，把表的主键设为标识

create table

yss_test

(

    id int identity(1,1) primary key not null,

     name varchar(50)

);

PostgreSQL，类型serial表示自动增加

create table

yss_test

(

  id SERIAL primary key ,  
  name character varying
);

MySQL，把表的主键设为auto_increment类型

create table

yss_test

(

    id int auto_increment primary key not null,

     name varchar(50)

);

DB2，把表的主键设为标识
yss_test
(

     id integer not null generated always as identity(start with 1,increment by 1) ,

     name varchar(50),

    primary key(id)

);