--- http://www.itbegin.com/app/study/self/unifiedselfstudy/10020001
--删除表hr.dept
--http://zhidao.baidu.com/question/743877745919926572.html
DROP TABLE hr.dept;
--创建表hr.dept
CREATE TABLE hr.dept
( deptno NUMBER(2),
name CHAR(4),
english int(10),
chinesh int(10),
math int(10),
cno char(4)
);
show columns from hr.dept;
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (1,'wz',10,20,30,'y');
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (2,'wz1',10,90,30,'d');
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (3,'wz2',10,90,90,'l');
insert
into hr.dept(deptno,name)
values (4,'wz4' );
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (5,'wzx',99,20,66,'y');
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (6,'wz1x',44,70,30,'d');
insert
into hr.dept(deptno,name,english,chinesh,math,cno)
values (7,'wz2x',66,88,55,'l');
-- 找到没有成绩的人---
/****
select deptno,name,english,chinesh,math
from hr.dept
where math is NULL
***
select deptno,name,math
from hr.dept
where math is not NULL
***
select deptno,name,math
from hr.dept
where deptno>1
order by math desc --asc
在线查找输出仅可以一条
**
select count(*)
from hr.dept
**
select deptno,name,math
from hr.dept
order by math --默认升序
**
-- select deptno,name,math from hr.dept where name LINK'_x%';--link '_x%';
--select max(math)
--from hr.dept
--各课程号所对应人数
select cno,count(cno)
from hr.dept
group by cno
**/
/*****
---循环添加记录 ---
--DECLARE @i int
--DECLARE @name char(4)
--开始 循环 插入数据--
--Set @i = 6
--WHILE @i < 10
--BEGIN
--Set @i =@i +1
--SET @name = RIGHT('00000' + CAST(@i AS varchar(10)),5)
--insert into hr.dept values(@i)--,@name,@i,@i,@i)
--END
***********/
