2.23

今天通过一天的听课
比如：
select * from T_UserInfo
where Address='邯郸' or Name='李哲'

select * from T_UserInfo where Name='李哲'

select * from T_UserInfo order by Age desc

select top 2* from T_UserInfo
--查询姓名的最后一个字为“哲”的数据，前边可以有一个或多个任意字符
select * from T_UserInfo WHERE Name LIKE '%哲'
--查询姓名的第一个字为“李”的数据，后边可以有一个或多个任意字符
select * from T_UserInfo WHERE Name LIKE '李%'

--查询姓名的最后一个字为“哲”的数据，前边可以有一个任意字符
select * from T_UserInfo where Name like '_哲'
--查询姓名的最后一个字为“李”的数据，后边可以有一个任意字符
select * from T_UserInfo WHERE Name LIKE '李_'

--in 运算符可以看成多个or 连接
select * from T_UserInfo WHERE
Age=27 or Age=20 or Age=19 or Age=21
select * from T_UserInfo WHERE Age in(30,20,19,21)

select * from T_UserInfo WHERE Age BETWEEN 19 and 30

select Name,Tell,Address from T_Userinfo where Name='李哲'
union
select Name,Tell,Address from T_UserInfo WHERE Age=21

--创建视图
create view v1 as
select top 3* from T_UserInfo WHERE Age>21

SELECT * FROM v1

UPDATE T_UserInfo SET Age=26 WHERE Name='姚宏波'
select * from T_UserInfo

UPDATE v1 SET Age=20 WHERE Name='李英哲'
DELETE FROM v1 WHERE Name='姚宏波'

select ROUND(AVG(numbs),1) from testgroup;
select SUM(numbs) from testgroup;
SELECT COUNT(*) FROM T_UserInfo;
SELECT MAX(Numbs) as numbs from testgroup;
SELECT min(Numbs) as numbs from testgroup;
SELECT min(name) as numbs from testgroup
SELECT MAX(name) as numbs from testgroup
SELECT MAX(fuhao) as numbs from testgroup
SELECT min(fuhao) as numbs from testgroup

select name, SUM(numbs)numbs from testgroup
group by(name) order by(numbs)

和
FileStream fs = new FileStream("C:\\Documents and Settings\\Administrator\\桌哩