SQL基础教程（第2版）第1章 数据库和SQL：练习题

CREATE TABLE Addressbook
 (
   regist_no    INTEGER      NOT NULL,
   name        VARCHAR(128) NOT NULL,
   address       VARCHAR(256) NOT NULL,
   tel_no       CHAR(10)     ,
   mail_address CHAR(20)     ,
   PRIMARY KEY (regist_no));

-- [PostgreSQL] [MySQL]
ALTER TABLE Addressbook ADD COLUMN postal_code CHAR(8) NOT NULL;

-- [Oracle]
ALTER TABLE Addressbook ADD (postal_code CHAR(8)) NOT NULL;