CREATE TABLE teacher1
(
    id   number,
    name varchar2(32),
    primary key (id)
);
 
select * from teacher1;
 
-- 插入數(shù)據(jù)
insert into teacher1(id, name) VALUES (7, 'zhangsan');
 
-- 插入數(shù)據(jù)后確認(rèn)無誤一定要提交，否則不會(huì)保存
commit ;
 
-- 修改表名
alter table teacher rename to teacher1;
 
-- 刪除表
drop table teacher1;
 
-- 提交事務(wù)
commit;

-- 創(chuàng)建序列名稱
create sequence teacher_seq;
 
-- 提取下一個(gè)值
select teacher_seq.nextval from DUAL;
 
-- 提取當(dāng)前值
select teacher_seq.currval from DUAL;

-- 先創(chuàng)建表
create table teacher(
    id number,
    name varchar2(32),
    pwd varchar2(32),
    primary key (id)
);
 
-- 再創(chuàng)建序列
create sequence teacher_seq;
 
-- 插入三條數(shù)據(jù)，將主鍵id設(shè)置為序列的下一個(gè)值，這個(gè)就相當(dāng)于自增
insert into teacher values (teacher_seq.nextval,'zs','123');
insert into teacher values (teacher_seq.nextval, 'lx', '456');
insert into teacher(id, name, pwd) values (teacher_seq.nextval, 'ww', '123');
 
-- 插入數(shù)據(jù)后確認(rèn)無誤一定要提交，否則不會(huì)保存
commit ;
 
select * from teacher;

-- 創(chuàng)建序列名稱
CREATE SEQUENCE 'sequence_name'
-- 遞增`n`的序列（默認(rèn)：`1`）
-- 如果`n`是正數(shù)就遞增
-- 如果`n`是負(fù)數(shù)就遞減
[INCREMENT BY 'n']
-- 開始值（遞增默認(rèn)是`minvalue`，遞減默認(rèn)是`maxvalue`）
[START WITH 'n'] 
-- 最大值
[{MAXVALUE 'n' | NOMAXVALUE}]
-- 最小值
[{MINVALUE 'n' | NOMINVALUE}]
-- 循環(huán) | 不循環(huán)（默認(rèn)：`NOCYCLE`）
[{CYCLE | 'NOCYCLE'}] 
-- 分配并存入到內(nèi)存中（默認(rèn)：`CACHE`）
[{'CACHE' 'n' | NOCACHE}]; 

-- 創(chuàng)建序列規(guī)則是：從100開始，每次+1
create sequence teacher_seq2 start with 100;
select teacher_seq2.nextval from DUAL;
 
-- 創(chuàng)建序列規(guī)則是：從5開始到100，超出最大值后無法創(chuàng)建
create sequence teacher_seq3 minvalue 5 maxvalue 100;
select teacher_seq3.nextval from DUAL;
 
-- 創(chuàng)建序列規(guī)則是：從1開始，步長為3的方式遞增
create sequence teacher_seq4 increment by 3;
select teacher_seq4.nextval from DUAL;
 
-- 創(chuàng)建復(fù)雜序列
create sequence teacher_seq5  increment by 4 start with -2 minvalue -2 maxvalue 10;
select teacher_seq5.nextval from DUAL;
 
-- 刪除其中一個(gè)序列
drop sequence teacher_seq5;

update teacher set pwd='123456' where id = 2;
update teacher set pwd='654321',name='lss' where id = 3;