Oracle 使用表总结

/*============创建Customer表==========*/
create table Customer
(
  Customer_id number(6) not null,
  Customer_name varchar2(50) not null,
  Password varchar2(20) not null,
  True_name varchar2(20),
  Email_address varchar2(50) not null,       --唯一
  Password_question varchar2(50) not null,
  Password_anwser varchar2(50) not null,
  Status char(1),                            --默认是1，取值0或1
  Customer_level char(1),                    --默认是1，取值1，2，3
  Score number(6),
  Register_date date,                        --默认为系统时间
  Login_time timestamp,
  Login_count number(6),
  Login_ip char(6)
);
/*===========创建Orders表==========*/
create table Orders
(
   Order_id varchar2(10) not null,
   Order_Customer_id number(6) not null,
   Order_date date not null,
   Order_price number not null
);
/*==========查询Customer表===========*/
select * from Customer

/*==========向表中添加数据===========*/
insert into Customer values
(220077,'wantingqiang','wtq','万廷强','lovezhqj@qq.com','你是哪个?','wtq','1','3',150,sysdate,sysdate,15789,'172.26')

/*==========修改表Customer===========*/
alter table Customer
    modify Login_ip char(16);
    
 /*=========修改第一条记录中的ip=====*/
 update Customer set Login_ip='172.26.3.145' where Customer_id='220077';--ip地址修改成功
 
 /*=========添加一个列===============*/
 alter table Customer
    add LoginOut_time date;                                             --新列增加成功
    
 /*=========删除一个列LoginOut_time========*/
 alter table Customer
    drop column LoginOut_time;                                          --列删除成功
    
 /*========给列添加注释===========*/
 comment on column
     Customer.Customer_Name is '客户姓名';
 
 /*========给表添加注释==========*/
 comment on table Customer is '客户表，为了保持与客户的联系';
 
 /*========重新命名表============*/
 alter table Customer rename to Customer_Change;
 
 select * from Customer_Change
 
 alter table Customer_Change rename to Customer;
 
 /*==========添加非空约束========*/
 alter table Customer 
    modify status not null;                                            --非空约束添加成功
    
 /*==========添加主键约束========*/
 alter table Customer
    add constraint customer_id_pk primary key(Customer_id);            --主键添加成功
 
 /*==========添加外键约束========*/
 --向Orders表中添加外键，与Customer表关联
 --在下面的列子末尾加上：
 --on delete 表示允许级联删除
 --on update 表示允许级联更新
 alter table Orders                                               
    add constraint Orders_Customer_fk  foreign key(Order_Customer_id) references Customer(Customer_id);
                                                                       --外键添加成功
 /*==========删除外键约束=========*/
 alter table Orders
    drop constraint "ORDERS_CUSTOMER_FK";                              --外键删除成功，这个要注意大小写哈  
 
 /*=========添加唯一约束========*/
 alter table Customer 
    add constraint un_email unique(Email_address);                     --添加唯一约束成功
 
 
 /*=========修改默认约束========*/
 alter table Customer
    modify Status default('1');
    
 /*=========添加检查约束========*/
 alter table Customer
    add constraint ck_status check(Status in ('1','0'));               --检查约束添加成功
 
 
 /*==========禁止检查约束=======*/
 alter table Customer 
    disable constraint ck_status;                                      --禁止成功
    
 /*==========激活检查约束=======*/
 alter table Customer
    enable constraint ck_status;                                       --激活成功
 
 /*==========删除检查约束========*/
 alter table Customer
    drop constraint ck_status;                                         --删除检查约束成功
 
/*==========最后事删除表========*/
 drop table Customer;                                                   --删除表成功