CREATE TABLE "W_WPRK_MODIFY" ("W_RKBH" VARCHAR2(6) NOT NULL, "W_RKWPBH" VARCHAR2(6) NOT NULL, "W_WPSX" VARCHAR2(1) NOT NULL, "W_WPLBM" VARCHAR2(3) NOT NULL, "W_RKWPMC" VARCHAR2(30) NOT NULL, "W_RKWPPP" VARCHAR2(30), "W_RKWPGG" VARCHAR2(30), "W_WPDWM" VARCHAR2(2) NOT NULL, "W_RKWPDJ" NUMBER(7,2) NOT NULL, "W_RKSL" NUMBER(4,0) NOT NULL, "W_RKSJ" DATE NOT NULL, "W_KCSL" NUMBER(4,0) NOT NULL, "W_CZSJ" DATE NOT NULL, "W_CZYBH" VARCHAR2(4) NOT NULL, "W_RKWPYT" VARCHAR2(60), "W_RKBZ" VARCHAR2(60)) ;
alter table tbl drop column col2;
ALTER TABLE tbl add (col2 varchar(10);
------------改名
alter table tbl drop column col2;
---------去掉一个字段