oracle增删改字段、建表、建序列

增加字段

alter table test1add (name varchar2(30) default ‘无名氏' not null);

修改字段

alter table test1modify (name varchar2(16) default ‘unknown');

删除字段

alter table test1drop column name;

建表

-- Create tablecreate table TBL_GNIDC_VISIT_LOG(  ID               VARCHAR2(32) not null,  DEVICE_IP        VARCHAR2(32),  ROOMNAME         VARCHAR2(32),  REPORT_LOGNAME   VARCHAR2(256),  REPORT_SERVER_IP VARCHAR2(32),  REPORT_TIME      VARCHAR2(32),  REPORT_NUM       VARCHAR2(32),  STRATEGY_STATE   VARCHAR2(32),  ACC_TIME         DATE not null)tablespace TBS_INMS  pctfree 10  initrans 1  maxtrans 255  storage  (    initial 16    next 8    minextents 1    maxextents unlimited  );

建序列

-- Create sequence create sequence TB_DEVREL_INFO_SEQUENCEminvalue 1maxvalue 9999999999999999999999999999start with 1increment by 1cache 20;

建视图

CREATE OR REPLACE VIEW ALLPOLICY ASSELECT * FROM DUAL;

to_char

“`sql
select id,device_ip,roomname,shortcmd,commandid,hit,to_char(coltime,’yyyy-mm-dd hh24:mi:ss’) coltime from GREENET_HIT_COUNT;