postgresql设置主键自增的方法

一 ：

CREATE TABLE customers  

(  

  customerid SERIAL primary key ,  

  companyname character varying,  

  contactname character varying,  

  phone character varying,  

 country character varying  

)  

二 :

CREATE SEQUENCE event_id_seq  

START WITH 1  

INCREMENT BY 1  NO MINVALUE  NO MAXVALUE  

CACHE 1;

alter table event alter column id set default nextval('event_id_seq');