oracle对用户、 表、字段的基本操作

1.创建用户并设置密码

    create user username identified by password ;

2.修改用户密码

    alter username identified by password ;

3.删除用户

    drop user username

4.赋予用户权限

赋予用户所有权限：

grant all privileges to username；

赋予用户部分权限：

grant connect to username;

grant resource to username;

grant create snapshot to username;

grant create synonym to username;

grant create table to username;

grant create view to username;

grant select any table to username;

grant create any trigger to username;

grant create any view to username;

grant select any dictionary to username;

grant unlimited tablespace to username;

5.添加表

create table sys_log (

log_id nvarchar2(36) not null,

create_time number(13) default null,

CONSTRAINT pk_logId PRIMARY KEY (log_id) --指定主键

)；

6.为表的某个字段添加索引

create INDEX createTime_index --索引名称

on

sys_log --表名 (create_time --字段名 );

7.插入数据

insert into sys_log (log_id,CREATE_TIME) values('1',1528787854000);

8.修改某个字段允许为空

ALTER TABLE 表名 MODIFY 字段名 字段类型 NULL;

9.增加字段

alter table sys_file add(

ip NVARCHAR2(20) default null

);

comment on column sys_file.ip is '上传人的ip';