mysql实例代码

-- 创建数据表stu
CREATE TABLE stu
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
sex VARCHAR(2) NOT NULL,
class_id INT,
age INT,
login_date DATE
);

-- 创建数据表class
CREATE TABLE class
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
grade VARCHAR(10) NOT NULL,
t_name VARCHAR(25) NOT NULL
);

-- 向数据表stu中插入记录
INSERT INTO stu VALUES
(101,'JAMES','M',01,20,'2014-07-31'),
(102,'HOWARD','M',01,24,'2015-07-31'),
(103,'SMITH','M',01,22,'2013-03-15'),
(201,'ALLEN','F',02,21,'2017-05-01'),
(202,'JONES','F',02,23,'2015-07-31'),
(301,'KING','F',03,22,'2013-01-01'),
(302,'ADAMS','M',03,20,'2014-06-01');


-- 向数据表class中插入记录
INSERT INTO class VALUES
(01,'MATH','One','JONH'),
(02,'HISTORY','Two','SIMON'),
(03,'PHYSICS','Three','JACKSON');

-- 查询每个班级年龄最大的学生
SELECT a.class_id,b.name,MAX(a.age)
FROM stu a,class b
WHERE a.class_id=b.id
GROUP BY a.class_id;

-- 查询学生JAMES所在班级名称和班主任姓名
SELECT a.name,b.name,b.t_name
FROM stu a,class b
WHERE a.class_id=b.id
AND a.name='JAMES';

-- 使用连接查询，查询所有学生的班级信息
SELECT a.id,a.name,b.name
FROM stu a,class b
WHERE a.class_id=b.id;

-- 在stu表中，计算每个班级各有多少名学生
SELECT b.name,COUNT(*)
FROM stu a,class b
WHERE a.class_id=b.id
GROUP BY b.name;

-- 在stu表中，计算不同班级学生的平均年龄
SELECT b.name,AVG(age)
FROM stu a,class b
WHERE a.class_id=b.id
GROUP BY b.name; 

-- 指定所有字段名称插入记录
INSERT INTO students
(id,name,sex,class_id,age,login_date)
 VALUES(101,'JAMES','M',01,20,'2014-07-31');

-- 不指定字段名称插入记录
INSERT INTO students VALUES
(102,'HOWARD','M',01,24,'2015-07-31');

-- 同时插入多条记录
INSERT INTO students VALUES
(103,'SMITH','M',01,22,'2013-03-15'),
(201,'ALLEN','F',02,21,'2017-05-01'),
(202,'JONES','F',02,23,'2015-07-31'),
(301,'KING','F',03,22,'2013-01-01'),
(302,'ADAMS','M',03,20,'2014-06-01');

-- 将学生JAMES的年龄增加1
UPDATE students SET age=age+1
WHERE name='JAMES';

-- 将学生JAMES的年龄增加1
UPDATE students SET sex='F',login_date='2016-08-31'
WHERE name='HOWARD';

-- 删除班级号为01的记录
DELETE FROM students
WHERE class_id=01;

-- 创建年龄超过22岁的学生的视图
CREATE VIEW stu_older(id,name,sex,age,login_date)
AS SELECT id,name,sex,age,login_date
FROM stu
WHERE age > 22;

-- 创建01班级的学生的视图
CREATE VIEW stu_class_one
(id,name,sex,age,login_date,class_name)
AS SELECT a.id,a.name,a.sex,a.age,a.login_date,b.name
FROM stu a,class b
WHERE class_id=01 AND a.class_id=b.id;

-- 更新学生HOWARD的年龄
UPDATE stu_class_one
SET age=age-1
WHERE name='HOWARD';

-- 查看创建的视图
SELECT * FROM information_schema.views\G

-- 删除创建的视图
DROP VIEW stu_orlder;
 

-- 【存储过程】（p299）
-- 创建存储过程
DELIMITER //
CREATE PROCEDURE getStuInfo
(IN id int(11))
BEGIN
SELECT id,a.name,b.name
FROM stu a,class b
WHERE a.class_id=b.id
AND a.id=id;
END //

-- 调用存储过程
DELIMITER ;
CALL getStuInfo(103);


-- 【触发器】（p338）
-- 创建数据表stu_login
CREATE TABLE stu_login
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
login_date DATE 
);

-- 创建数据表stu_years
CREATE TABLE stu_years
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
years INT 
);

-- 创建触发器get_years
CREATE TRIGGER get_years
AFTER INSERT ON stu_login
FOR EACH ROW
INSERT INTO stu_years
VALUES(NEW.id,NEW.name,
YEAR(CURDATE())-YEAR(NEW.login_date));

-- 向stu_login
INSERT INTO stu_login VALUES
(101,'JAMES','2014-07-31'),
(102,'HOWARD','2015-07-31'),
(103,'SMITH','2013-03-15');


-- 【索引】（p273）
-- 创建学生索引表
CREATE TABLE stu_index
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
sex VARCHAR(2) NOT NULL,
age INT NOT NULL,
login_date DATE NOT NULL,
UNIQUE INDEX uni_idx(id),
INDEX multi_idx(name(25),sex(2))
);

-- 创建班级索引表
CREATE TABLE class_index
(
id INT NOT NULL PRIMARY KEY,
name VARCHAR(25) NOT NULL,
grade VARCHAR(10) NOT NULL,
t_name VARCHAR(25) NOT NULL
);

-- 添加唯一索引
ALTER TABLE class_index
ADD UNIQUE INDEX uni_c_idx(id DESC);

-- 添加普通索引
ALTER TABLE class_index
ADD INDEX com_grade_idx(grade);

-- 添加组合索引
CREATE INDEX multi_col_idx
ON class_index(name,grade);

-- 删除索引
ALTER TABLE class_index
DROP INDEX com_tname_idx;

DROP INDEX multi_col_idx ON class_index;


-- 【用户与权限】（p368）
-- 创建新用户
GRANT SELECT,UPDATE(id,name,grade,t_name)
ON class
TO 'adminNew'@'localhost' IDENTIFIED BY '123'
WITH MAX_CONNECTIONS_PER_HOUR 30;

-- 查询账户信息
SELECT host,user,select_priv,update_priv
FROM mysql.user
WHERE user='adminNew';

-- 查询表权限信息
SELECT host,db,user,table_name,table_priv,column_priv
FROM mysql.tables_priv
WHERE user='adminNew';

-- 查询列权限信息
SELECT host,db,user,table_name,column_priv,column_priv
FROM mysql.columns_priv
WHERE user='adminNew';

-- 查看账户的权限信息
SHOW GRANTS FOR 'adminNew'@'localhost';

-- 收回账户权限
REVOKE SELECT,UPDATE
ON school.class
FROM 'adminNew'@'localhost';

-- 删除用户
DROP USER 'adminNew'@'localhost';


-- 【备份和还原】（p399）
-- 使用mysqldump备份
C:\Users\USER>mysqldump -u root -p school students > D:\mysql_backup\students_bk.sql

-- 使用mysqldump还原
SOURCE D:/mysql_backup/students_bk.sql;

-- 数据库备份
SELECT * FROM school.students
INTO OUTFILE 'C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/students_out.txt'
FIELDS
TERMINATED BY ','
ENCLOSED BY '\"'
LINES
STARTING BY '<'
TERMINATED BY '>\r\n';

-- 数据库还原
LOAD DATA INFILE 'C:/ProgramData/MySQL/MySQL Server 5.7/Uploads/students_out.txt'
INTO TABLE school.students
FIELDS
TERMINATED BY ','
ENCLOSED BY '\"'
LINES
STARTING BY '<'
TERMINATED BY '>\r\n';