【Oracle笔记】最详细的操作命令大全（基础版）

create table mytest(id varchar2(2 char),name varchar2(3 char));

insert into mytest(id,name) values('01','tom');

select * from mytest;

update mytest set name='mm' where id='03';

delete from mytest where id='03';

alter table mytest add (address varchar2(100 char));

alter table mytest rename column address to addr;
alter table mytest modify address varchar2(200 char);

alter table mytest drop (addr);

alter table mytest rename to mytest2;

delete from mytest;--删除数据，可回滚
truncate table mytest;--删除数据，不可回滚，并重置计数器

drop table mytest;--删除表，可恢复（flashback table mytest to before drop ）
drop table mytest purge;--删除表，无法恢复

alter table mytest read only;--只读
alter table mytest read write;--恢复读写

select table_name from user_tables;

select * from mytest order by id desc;

select sex from mytest group by sex;

create table mytest_new as select * from mytest;--备份表结构和数据
create table mytest_new as select * from mytest where 1=2; --只备份表结构
insert into mytest_new select * from mytest；--只备份表数据 

alter table mytest add constraint name primary key(name); 

alter table mytest drop constraint id;

create  index  index_name  on  table(column_name1,column_name2);

drop index index_name;

create synonym tablenameB for 数据库名字.tablenameA;

drop synonym tablenameB;