MySQL.session.sql

-- Active: 1709821089199@@127.0.0.1@3306@s1
SELECT *
FROM emp;
-- SELECT workid, name FROM emp WHERE workid >= 3;
-- SELECT * FROM emp WHERE age = 20;
-- SELECT * FROM emp WHERE idcard IS NOT NULL;
-- INSERT INTO emp VALUES(7, '7', 'cjw','0', 30, '', '', '2003-01-01');
-- SELECT * FROM emp WHERE address = '';
-- SELECT * FROM emp WHERE age BETWEEN 19 AND 20 OR id BETWEEN 1 AND 5;
-- SELECT * FROM emp WHERE age IN(19, 30);
-- SELECT * FROM emp WHERE name LIKE '__';
-- SELECT * FROM emp WHERE age LIKE '%0';
-- SELECT MAX(age) FROM emp WHERE age = 20;
-- SELECT COUNT(gender) FROM emp GROUP BY gender;
-- SELECT gender, COUNT(age) FROM emp GROUP BY gender;
-- SELECT address, COUNT(*) FROM emp WHERE age < 20 GROUP BY address;
-- SELECT name, age, day FROM emp ORDER BY age ASC, day DESC;
-- SELECT * FROM emp LIMIT 0, 5;
-- SELECT CONCAT("Hello", "World");
-- SELECT LOWER("HEllo");
-- SELECT UPPER("heLLO");
-- SELECT LPAD("1", 5, "-");
-- SELECT RPAD("1", 5, "-");
-- SELECT TRIM("  Hello World  ");
-- UPDATE emp SET workid = LPAD(workid, 5, '0');
-- SELECT CEIL(1.5);
-- SELECT FLOOR(2.4);
-- SELECT CURDATE();
-- SELECT CURTIME();
-- SELECT NOW();
-- SELECT YEAR(NOW());
-- SELECT MONTH(NOW());
-- SELECT DAY(NOW());
-- SELECT DATEDIFF('2024-01-01', '2024-10-01');
-- SELECT DATEDIFF('2024-10-1', '2024-1-1');
-- SELECT name, day FROM emp ORDER BY DATEDIFF(CURDATE(), day) DESC;
-- SELECT name, day FROM emp ORDER BY DATEDIFF(CURDATE(), day) ASC;
SELECT IF(TRUE, "YES", "NO");
SELECT IFNULL("YES", "NO");
SELECT IFNULL(NULL, "NO");
SELECT name,
    CASE
        address
        WHEN 3 THEN "一"
        WHEN 2 THEN "一"
        ELSE "二"
    END
FROM emp;
SELECT name,
    CASE
        WHEN address = 3 THEN '三'
        WHEN address = 2 THEN '二'
        WHEN address = 1 THEN '一'
        ELSE '10'
    END
FROM emp;
CREATE TABLE USER (
    id INT PRIMARY KEY AUTO_INCREMENT COMMENT "主键",
    name VARCHAR(10) NOT NULL UNIQUE COMMENT "姓名",
    age int CHECK(
        age > 0
        and age <= 120
    ) COMMENT "年龄",
    status CHAR(1) DEFAULT '1' COMMENT "状态",
    gender CHAR(1) COMMENT "性别"
) COMMENT "用户表"
SELECT *
FROM `user`;
INSERT INTO `user`
VALUES (1, "tom", 19, "1", "男"),
    (2, "jerry", 25, "0", "男");
INSERT INTO `user` (name, age, status, gender)
VALUES ("jack", 19, "1", "男");
INSERT INTO `user` (name, age, status, gender)
VALUES (NULL, 19, "1", "男");
INSERT INTO `user` (name, age, status, gender)
VALUES ("rose", 19, "1", "男");
INSERT INTO `user` (name, age, gender)
VALUES ("mike", 19, "男");
create table emp(
    id int auto_increment comment 'ID' primary key,
    name varchar(50) not null comment '姓名',
    age int comment '年龄',
    job varchar(20) comment '职位',
    salary int comment '薪资',
    entrydate date comment '入职时间',
    managerid int comment '直属领导ID',
    dept_id int comment '部门ID'
) comment '员工表';
create table dept(
    id int auto_increment comment 'ID' primary key,
    name varchar(50) not null comment '部门名称'
) comment '部门表';
INSERT INTO dept (id, name)
VALUES (1, '研发部'),
    (2, '市场部'),
    (3, '财务部'),
    (4, '销售部'),
    (5, '总经办');
SELECT *
FROM dept;
SELECT *
FROM emp;
INSERT INTO emp (
        id,
        name,
        age,
        job,
        salary,
        entrydate,
        managerid,
        dept_id
    )
VALUES (1, '金庸', 66, '总裁', 20000, '2000-01-01', null, 5),
    (2, '张无忌', 20, '项目经理', 12500, '2005-12-05', 1, 1),
    (3, '杨逍', 33, '开发', 8400, '2000-11-03', 2, 1),
    (4, '韦一笑', 48, '开
发', 11000, '2002-02-05', 2, 1),
    (5, '常遇春', 43, '开发', 10500, '2004-09-07', 3, 1),
    (
        6,
        '小昭',
        19,
        '程
序员鼓励师',
        6600,
        '2004-10-12',
        2,
        1
    );
ALTER TABLE emp
ADD CONSTRAINT fk_emp_dept_id Foreign Key (dept_id) REFERENCES dept(id);
ALTER TABLE emp DROP FOREIGN KEY fk_emp_dept_id;


ALTER TABLE emp
ADD CONSTRAINT fk_emp_dept_id FOREIGN KEY (dept_id) REFERENCES dept(id) ON UPDATE
SET NULL ON DELETE
SET NULL;
create table student(
    id int auto_increment primary key comment '主键ID',
    name varchar(10) comment '姓名',
    no varchar(10) comment '学号'
) comment '学生表';
insert into student
values (null, '黛绮丝', '2000100101'),
    (null, '谢逊', '2000100102'),
    (null, '殷天正', '2000100103'),
    (null, '韦一笑', '2000100104');
create table course(
    id int auto_increment primary key comment '主键ID',
    name varchar(10) comment '课程名称'
) comment '课程表';
insert into course
values (null, 'Java'),
    (null, 'PHP'),
    (null, 'MySQL'),
    (null, 'Hadoop');
create table student_course(
    id int auto_increment comment '主键' primary key,
    studentid int not null comment '学生ID',
    courseid int not null comment '课程ID',
    constraint fk_courseid foreign key (courseid) references course (id),
    constraint fk_studentid foreign key (studentid) references student (id)
) comment '学生课程中间表';
insert into student_course
values (null, 1, 1),
    (null, 1, 2),
    (null, 1, 3),
    (null, 2, 2),
    (null, 2, 3),
    (null, 3, 4);

SELECT * FROM course;
SELECT * FROM student;
SELECT * FROM student_course;
SELECT * FROM user;




create table dept(
id int auto_increment comment 'ID' primary key,
name varchar(50) not null comment '部门名称'
)comment '部门表';
INSERT INTO dept (id, name) VALUES (1, '研发部'), (2, '市场部'),(3, '财务部'), (4,
'销售部'), (5, '总经办'), (6, '人事部');

create table emp(
id int auto_increment comment 'ID' primary key,
name varchar(50) not null comment '姓名',
age int comment '年龄',
job varchar(20) comment '职位',
salary int comment '薪资',
entrydate date comment '入职时间',
managerid int comment '直属领导ID',
dept_id int comment '部门ID'
)comment '员工表';

alter table emp add constraint fk_emp_dept_id foreign key (dept_id) references
dept(id);
INSERT INTO emp (id, name, age, job,salary, entrydate, managerid, dept_id)
VALUES
(1, '金庸', 66, '总裁',20000, '2000-01-01', null,5),
(2, '张无忌', 20, '项目经理',12500, '2005-12-05', 1,1),
(3, '杨逍', 33, '开发', 8400,'2000-11-03', 2,1),
(4, '韦一笑', 48, '开发',11000, '2002-02-05', 2,1),
(5, '常遇春', 43, '开发',10500, '2004-09-07', 3,1),
(6, '小昭', 19, '程序员鼓励师',6600, '2004-10-12', 2,1),
(7, '灭绝', 60, '财务总监',8500, '2002-09-12', 1,3),
(8, '周芷若', 19, '会计',48000, '2006-06-02', 7,3),
(9, '丁敏君', 23, '出纳',5250, '2009-05-13', 7,3),
(10, '赵敏', 20, '市场部总监',12500, '2004-10-12', 1,2),
(11, '鹿杖客', 56, '职员',3750, '2006-10-03', 10,2),
(12, '鹤笔翁', 19, '职员',3750, '2007-05-09', 10,2),
(13, '方东白', 19, '职员',5500, '2009-02-12', 10,2),
(14, '张三丰', 88, '销售总监',14000, '2004-10-12', 1,4),
(15, '俞莲舟', 38, '销售',4600, '2004-10-12', 14,4),
(16, '宋远桥', 40, '销售',4600, '2004-10-12', 14,4),
(17, '陈友谅', 42, null,2000, '2011-10-12', 1,null);

SELECT * FROM emp;
SELECT * FROM dept;


SELECT * FROM emp, dept WHERE emp.dept_id = dept.id;
SELECT emp.name, dept.name FROM emp, dept WHERE emp.dept_id = dept.id;

SELECT emp.name, dept.name FROM emp INNER JOIN dept ON emp.dept_id = dept.id;



SELECT * FROM emp LEFT OUTER JOIN dept ON emp.dept_id = dept.id;
SELECT emp.*, dept.id FROM emp LEFT OUTER JOIN dept ON emp.dept_id = dept.id;

SELECT * FROM emp RIGHT OUTER JOIN dept ON emp.dept_id = dept.id;

SELECT dept.*, emp.* FROM emp RIGHT OUTER JOIN dept ON emp.dept_id = dept.id;


SELECT e1.name AS employee, e2.name AS employer FROM emp AS e1 JOIN emp AS e2 ON e1.managerid = e2.id;

SELECT e1.name AS employee, e2.name AS employer FROM emp AS e1 LEFT OUTER JOIN emp AS e2 ON e1.managerid = e2.id;


SELECT * FROM emp WHERE emp.salary < 5000
UNION ALL
SELECT * FROM emp WHERE emp.age > 50;


SELECT * FROM emp WHERE emp.dept_id = (SELECT dept.id FROM dept WHERE name = "销售部");

SELECT * FROM emp WHERE entrydate > (SELECT entrydate FROM emp WHERE name = "方东白");

SELECT * FROM emp WHERE dept_id in (SELECT id FROM dept WHERE name = "销售部" OR name = "市场部");

SELECT * FROM emp WHERE salary > ALL ( SELECT salary FROM emp WHERE emp.dept_id = (SELECT id FROM dept WHERE dept.name = "财务部"));

SELECT * FROM emp;


SELECT * FROM emp WHERE salary > ANY ( SELECT salary FROM emp WHERE emp.dept_id = (SELECT id FROM dept WHERE dept.name = "研发部"));

SELECT job, salary FROM emp WHERE name = "鹿杖客" OR name = "宋远桥";
SELECT * FROM emp WHERE (job, salary) IN (SELECT job, salary FROM emp WHERE name = "鹿杖客" OR name = "宋远桥");

SELECT * FROM (SELECT * FROM emp WHERE entrydate > "2006-01-01") AS e LEFT JOIN dept AS d ON d.id = e.dept_id;


create table salgrade(
grade int,
losal int,
hisal int
) comment '薪资等级表';

insert into salgrade values (1,0,3000);
insert into salgrade values (2,3001,5000);
insert into salgrade values (3,5001,8000);
insert into salgrade values (4,8001,10000);
insert into salgrade values (5,10001,15000);
insert into salgrade values (6,15001,20000);
insert into salgrade values (7,20001,25000);
insert into salgrade values (8,25001,30000);


SELECT e.name, e.age, d.name FROM emp AS e, dept as d WHERE e.dept_id = d.id;

SELECT * FROM emp AS e INNER JOIN dept AS d ON e.dept_id = d.id WHERE e.age < 30;

SELECT DISTINCT d.* FROM emp AS e INNER JOIN dept AS d ON e.dept_id = d.id;

SELECT * FROM emp AS e LEFT OUTER JOIN dept AS d ON e.dept_id = d.id WHERE e.age > 40;
SELECT * FROM emp AS e WHERE e.age > 40;

SELECT e.name, s.grade FROM emp AS e, salgrade AS s WHERE e.salary >= s.losal and e.salary <= s.hisal;


START TRANSACTION;
SELECT @@AUTOCOMMIT;
SET @@AUTOCOMMIT = 0;
DROP TABLE IF EXISTS `account`;
create table account(
id int primary key AUTO_INCREMENT comment 'ID',
name varchar(10) comment '姓名',
money double(10,2) comment '余额'
) comment '账户表';

insert into account(name, money) VALUES ('张三',2000), ('李四',2000);

SELECT * FROM `account`;

UPDATE `account` SET money = money - 1000 WHERE name = "张三";
UPDATE `account` SET money = money + 1000 WHERE name = "李四";

COMMIT;
ROLLBACK;