创建表:
例如:CREATE TABLE DEPT(
EPTNO NUMBER(2) CONSTRAINT PK_DEPT PRIMARY KEY,
DNAME VARCHAR2(14),
LOC VARCHAR2(13)) ;
更新字段名 | alter table TABLE_NAME rename column column_old to column_new; |
添加字段 添加多个字段 | alter table TABLE_NAME add COLUMN_NAME varchar(10); alter table TABLE_NAME add (COLUMN_NAME varchar(10),COLUMN_NAME varchar(20)); |
删除字段 | alter table TABLE_NAME drop column COLUMN_NAME; |
添加字段并附值 | alter table TABLE_NAME ADD COLUMN_NAME NUMBER(1) DEFAULT 1; |
修改字段数据类型 | alter table tablename modify filedname varchar2(20); |
添加字段注释 | comment on column test1.age is '年龄'; |
alter table student add constraint pk_student primary key(studentid);