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;
comment on table ods_user_inf is 'The table is created to store the user information';--查看备注:
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;