杂七杂八

    技术2022-05-11  6

    -------------------------------------  创建表1 1  create table lwc_d   2  (id number(7) primary key,   3  name varchar2(15) not null   4  ,   5  phone varchar2(11) not null unique,   6  email varchar2(25) unique check(email like '%_@_%),   7  qq number(12) unique,   8  sex varchar2(3)   9* ) SQL> 6   6* email varchar2(25) unique check(email like '%_@_%), SQL> c/'%_@_%/'%_@_%'   6* email varchar2(25) unique check(email like '%_@_%'), ------------------- 创建表2 create table lwc_e (id number(7) primary key, name varchar2(15) not null, phone varchar2(11) not null unique, email varchar2(25) unique check(email like '%_@_%'), qq number(12) unique, sex varchar2(3) default 'm' ); ----------------------------------------- 创建tableA表 create table tableAlwc (id number(7) primary key, value varchar2(15) not null ); 创建tableB表 create table tableBlwc (id number(7) primary key, value varchar2(15) not null ); ---------------- insert into tableAlwc values(&id,'&value'); ---------------- insert into tableBlwc values(&id,'&value'); 练习答案: update tableAlwc set value=(select value from tableBlwc where id=tableAlwc.id); -------------------------------- 练习插入 1.插入一整行 insert into lwc_d values(466,'liang','13666','ddhh@163.com',445568,'m'); 2.插入对应的列 insert into lwc_d(id,name,phone) values(466,'liang','23235623');  //错的,因为表创建的时候没有默认值 3.用&来插入(创建新表时最好的方式) insert into lwc_d values(&id,'&name','&phone','&email',&qq,'&sex');  select table_name from user_tables where table_name like '%LWC%'; 在服务器里面利用内存空间在作为回滚段


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