오라클 DDL

DROP TABLE STUDENTS;

CREATE TABLE STUDENTS188

(

  "SID" VARCHAR2(30),

  "PWD" VARCHAR2(30) ,

  "NAME" VARCHAR2(30),

  "GENDER" VARCHAR2(8),

  "AGE" NUMBER ,

  "BIRTHDAY" CHAR(10),

  "MAJOR" VARCHAR2(50),

  "ADDRESS" NVARCHAR2(300),

  "PHONE" VARCHAR2(13),

  "SSN" CHAR(14),

  "IP" VARCHAR(15),

  "REGDATE" DATE

);

ALTER TABLE STUDENTS188 ADD CITY VARCHAR2(30);

ALTER TABLE STUDENTS188 DROP COLUMN CITY ;

ALTER TABLE STUDENTS188 MODIFY REGDATE TIMESTAMP ;