Use xsxk;
WITH c_count(id,xb,rs)
AS (SELECT 班级,性别,count(*)
FROM XS GROUP BY 班级,性别 )
SELECT * FROM c_count
-- WITH 的意义
SELECT * INTO #Tem
FROM XS
SELECT *
FROM #Tem
SELECT *
FROM #Tem T
WHERE T.出生日期 BETWEEN '1995-02-09' AND '1995-02-19' -- OK
SELECT TT.学号, CASE WHEN 总学分>60 THEN '优秀' ElSE '不太好' END AS 级别
FROM #Tem TT
SELECT *
FROM [dbo].[Test_2019_t]
SELECT * INTO #Test
FROM [dbo].[xs]
SELECT *
FROM #Test
-- 1. Between…And
SELECT *
FROM XS
WHERE 出生日期
between '1995-02-09' and '1995-07-02'
order by 出生日期 desc
SELECT *
FROM XS
WHERE 总学分
--between 10 and 20
IN (20,21)
order by 总学分 asc
-- 2. IS NULL
SELECT *
FROM XS
WHERE 备注 IS NULL;
-- 3. TOP
SELECT TOP 10 *
FROM XS
-- 4. UNION 去重的作用 -- UNION ALL
SELECT 姓名,学号 -- 表1
FROM xs
UNION
SELECT 姓名,学号 -- 表2 链接起来-- 表三的感觉,
FROM xs3
ORDER BY 学号 ASC
-- UNION --
--表3
SELECT 姓名,学号 -- 表1
FROM xs
WHERE 学号='14311001'
INSERT INTO xs3(姓名,学号)
VALUES('杨天','14311001')
-- 嵌套查询
SELECT 学号 -- 表1
FROM xs3
WHERE 学号='14311001'
SELECT *
FROM XS
WHERE 学号 IN ( SELECT 学号 -- 表1
FROM xs3 ) --('','')
-- inner join
-- left join
-- right join
SELECT *
FROM XS t1
INNER JOIN XS3 t2
ON t1.学号=t2.学号
SELECT *
FROM XS t1
RIGHT JOIN XS3 t2
ON t1.学号=t2.学号
-- 表跟表之间的一个关联关系
use xsxk
select *
from XS3
--
-- CASE WHEN THEN ELSE
SELECT 学号,CASE WHEN 总学分>19 THEN '优秀' ELSE '良' END AS 成绩
FROM XS
-- UPATE
SELECT *
FROM XS3
UPDATE XS3
SET 姓名='xx' ,出生日期='1991-04-05'
WHERE 学号='14341001'
-- 更新
-- 删除
DELETE FROM XS3
WHERE 学号='14311001' -- IN () ，IN
-- INSERT
-- 创建视图 --命令创建
CREATE VIEW view_xs1
AS SELECT 学号,姓名 FROM XS -- 块
-- 1
--2
--3
GO
SELECT *
FROM view_xs1
-- 修改 视图 ALTER 修改
-- DROP
DROP VIEW [dbo].[View_SS] --修改
-- View Insert
SELECT * FROM xs
INSERT INTO view_xs1
VALUES('10000007','王二'); -- 思考,如果我的视图内部有两个以上的表,3,4 ,
-- Insert 思考
SELECT *
FROM view_xs1
UPDATE view_xs1 SET 姓名='ts'
--SELECT * FROM view_xs1
WHERE 学号 = '10000007' --保证条件正确性
SELECT * FROM view_xs1
DELETE view_xs1
WHERE 学号 = '10000007'
SELECT COUNT(*) FROM xs
-- 存储过程
CREATE PROCEDURE QuerT
AS
SELECT * FROM XS
CREATE PROCEDURE Quer @xh char(10)
AS
SELECT * FROM xs WHERE 学号=@xh
-- 如何使用
EXEC [dbo].[QuerT]
EXEC [dbo].[Quer] '14311001' -- 传参数
EXEC sp_helptext Quer
-- 存储过程的查看
-- sp_rename Quer,Quer_NEW --重命名
--
DROP PROCEDURE QuerT