本文详细介绍了Oacle数据库中表的基本操作:
如何创建数据库表
--方法1: 用create table创建表
- create table ods_user_inf
- (
- user_id number,user_num varchar2(20),user_name varchar2(30),nickname varchar2(30),status varchar2(10),gender varchar2(1),birthday date,email varchar2(50),telephone varchar2(20),mobile varchar2(20),address varchar2(300),department_id number
- );
--方法2: 基于现有表创建表结构
- create table ods_user
- as
- select *
- from ods_user_inf
- where 1=2;
- alter table ods_user_active rename to ods_user_effective;
--查看备注:
- comment on table ods_user_inf is 'The table is created to store the user information';
- select * from user_tab_comments where comments is not null;
如何删除表
- drop table ods_user_inf_active;
- alter table ods_user_inf add (salary number(22,2),bonus number(22,2));
- alter table ods_user_inf add (type varchar2(20));
- alter table ods_user_inf add (attribute1 varchar2(20));
- alter table ods_user_inf add (attribute1 varchar2(20));
- alter table ods_user_inf rename column type to user_type;
- alter table ods_user_inf modify user_type varchar2(25);
- comment on column ods_user_inf.user_num is 'user number';
--查看备注:
- select * from user_col_comments where comments is not null and table_name='ODS_USER_INF';
- alter table ods_user_inf drop column attribute2;