[數據庫]數據庫系統概論·課本驗證

注:MySQL運行環境。持續更新。by echo

-- DROP DATABASE echo;
-- 新建數據庫
CREATE DATABASE echo;


USE echo;


CREATE TABLE Student (
Sno CHAR (9) PRIMARY KEY,
Sname CHAR (20) UNIQUE,
Ssex CHAR (2),
Sage SMALLINT,
Sdept CHAR (20)
);


CREATE TABLE Course (
Cno CHAR (4) PRIMARY KEY,
Cname CHAR (40) NOT NULL,
Cpno CHAR (4),
Ccredit SMALLINT,
FOREIGN KEY (Cpno) REFERENCES Course (Cno)
);


CREATE TABLE SC (
Sno CHAR (9),
Cno CHAR (4),
Grade SMALLINT,
PRIMARY KEY (Sno, Cno),
FOREIGN KEY (Sno) REFERENCES Student (Sno),
FOREIGN KEY (Cno) REFERENCES Course (Cno)
);


/* 注意！
sql server中爲ALTER TABLE ... ALTER COLUMN 
orcale中爲ALTER TABLE ... MODIFY 
*/
-- 修改基本表 
-- RESTRICT 不能有限制（默認） CASCADE 強制刪除，相關也刪除（級聯） 
ALTER TABLE Student ADD COLUMN aa SMALLINT;


ALTER TABLE Student MODIFY COLUMN aa INT;


-- 更改類型
ALTER TABLE Student CHANGE COLUMN aa cc SMALLINT;


-- 更改列名和類型
ALTER TABLE Student DROP COLUMN cc CASCADE;


-- 新增數據
INSERT INTO Student (Sno, Sname, Ssex, Sage, Sdept)
VALUE
(
201215121,
'李勇',
'男',
20,
'CS'
),
(
201215122,
'劉晨',
'女',
19,
'CS'
),
(
201215123,
'王敏',
'女',
18,
'MA'
),
(
201215125,
'張立',
'男',
19,
'IS'
);


INSERT INTO Course (Cno, Cname, Cpno, Ccredit)
VALUE
(1, '數據庫', 5, 4),
(2, '數學', NULL, 2),
(3, '信息系統', 1, 4),
(4, '操作系統', 6, 3),
(5, '數據結構', 7, 4),
(6, '數據處理', NULL, 2),
(7, 'PASCAL語言', 6, 4);


INSERT INTO SC (Sno, Cno, Grade)
VALUE
(201215121, 1, 92),
(2015121, 2, 85),
(2015121, 3, 88),
(2015122, 2, 90),
(2015122, 3, 80);


-- 全表查詢
SELECT
*
FROM
echo.Student;


SELECT
*
FROM
echo.Course;


SELECT
*
FROM
SC;