表名：worker-- 表中字段均為中文，比如 部門號(hào) 工資 職工號(hào) 參加工作 等
CREATE TABLE `worker` (
 `部門號(hào)` int(11) NOT NULL,
 `職工號(hào)` int(11) NOT NULL,
 `工作時(shí)間` date NOT NULL,
 `工資` float(8,2) NOT NULL,
 `政治面貌` varchar(10) NOT NULL DEFAULT '群眾',
 `姓名` varchar(20) NOT NULL,

 `性別` ENUM('男','女'),
 `出生日期` date NOT NULL,
 PRIMARY KEY (`職工號(hào)`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC;
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (101, 1001, '2015-5-4', 3500.00, '群眾', '張三', '男','1990-7-1');
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (101, 1002, '2017-2-6', 3200.00, '團(tuán)員', '李四','女' '1997-2-8');
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (102, 1003, '2011-1-4', 8500.00, '黨員', '王亮','男', '1983-6-8');
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (102, 1004, '2016-10-10', 5500.00, '群眾', '趙六', '男','1994-9-5');
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (102, 1005, '2014-4-1', 4800.00, '黨員', '錢七','女' '1992-12-30');
INSERT INTO `worker` (`部門號(hào)`, `職工號(hào)`, `工作時(shí)間`, `工資`, `政治面貌`, `姓名`,`性別`, `出生
日期`) VALUES (102, 1006, '2017-5-5', 4500.00, '黨員', '孫八','女', '1996-9-2');

-- 查詢所有數(shù)據(jù)驗(yàn)證
SELECT * FROM worker;

-- 1、顯示所有職工的基本信息
SELECT * FROM worker;

-- 2、查詢所有職工所屬部門的部門號(hào)，不顯示重復(fù)的部門號(hào)
SELECT DISTINCT `部門號(hào)` FROM worker;

-- 3、求出所有職工的人數(shù)
SELECT COUNT(*) AS `職工人數(shù)` FROM worker;

-- 4、列出最高工資和最低工資
SELECT MAX(`工資`) AS `最高工資`, MIN(`工資`) AS `最低工資` FROM worker;

-- 5、列出職工的平均工資和總工資
SELECT AVG(`工資`) AS `平均工資`, SUM(`工資`) AS `總工資` FROM worker;

-- 6、創(chuàng)建新表工作日期表
CREATE TABLE `工作日期表` AS SELECT `職工號(hào)`, `姓名`, `工作時(shí)間` FROM worker;

-- 7、顯示所有女職工的年齡
SELECT * FROM WORKER WHERE `性別` = '女';

-- 8、列出所有姓劉的職工信息
SELECT `職工號(hào)`, `姓名`, `出生日期` FROM worker WHERE `姓名` LIKE '劉%';

-- 9、列出1960年以前出生的職工
SELECT `姓名`, `工作時(shí)間` FROM worker WHERE `出生日期` < '1960-01-01';

-- 10、列出工資在1000-2000之間的職工
SELECT `姓名` FROM worker WHERE `工資` BETWEEN 1000 AND 2000;

-- 11、列出姓陳或李的職工
SELECT `姓名` FROM worker WHERE `姓名` LIKE '陳%' OR `姓名` LIKE '李%';

-- 12、列出部門號(hào)為2和3的職工信息
SELECT `職工號(hào)`, `姓名`, IF(`政治面貌` = '黨員', '是', '否') AS `黨員否` 
FROM worker WHERE `部門號(hào)` IN (102, 103); -- 根據(jù)實(shí)際部門號(hào)調(diào)整

-- 13、按出生日期排序
SELECT * FROM worker ORDER BY `出生日期`;

-- 14、顯示工資前三名的職工
SELECT `職工號(hào)`, `姓名` FROM worker ORDER BY `工資` DESC LIMIT 3;

-- 15、統(tǒng)計(jì)各部門黨員人數(shù)
SELECT `部門號(hào)`, COUNT(*) AS `黨員人數(shù)` FROM worker WHERE `政治面貌` = '黨員' GROUP BY `部門號(hào)`;

-- 16、統(tǒng)計(jì)各部門工資情況
SELECT `部門號(hào)`, SUM(`工資`) AS `總工資`, AVG(`工資`) AS `平均工資` FROM worker GROUP BY `部門號(hào)`;

-- 17、列出總?cè)藬?shù)大于4的部門
SELECT `部門號(hào)`, COUNT(*) AS `總?cè)藬?shù)` FROM worker GROUP BY `部門號(hào)` HAVING COUNT(*) > 4;

CREATE  TABLE student (
id  INT(10)  NOT NULL  UNIQUE  PRIMARY KEY ,
name  VARCHAR(20)  NOT NULL ,
sex  VARCHAR(4) ,
birth  YEAR,
department  VARCHAR(20) ,
address  VARCHAR(50)
);
創(chuàng)建score表。SQL代碼如下：
CREATE  TABLE score (
id  INT(10)  NOT NULL  UNIQUE  PRIMARY KEY  AUTO_INCREMENT ,
stu_id  INT(10)  NOT NULL ,
c_name  VARCHAR(20) ,
grade  INT(10)
);

向student表插入記錄的INSERT語(yǔ)句如下：
INSERT INTO student VALUES( 901,'張老大', '男',1985,'計(jì)算機(jī)系', '北京市海淀區(qū)');
INSERT INTO student VALUES( 902,'張老二', '男',1986,'中文系', '北京市昌平區(qū)');
INSERT INTO student VALUES( 903,'張三', '女',1990,'中文系', '湖南省永州市');
INSERT INTO student VALUES( 904,'李四', '男',1990,'英語(yǔ)系', '遼寧省阜新市');
INSERT INTO student VALUES( 905,'王五', '女',1991,'英語(yǔ)系', '福建省廈門市');
INSERT INTO student VALUES( 906,'王六', '男',1988,'計(jì)算機(jī)系', '湖南省衡陽(yáng)市');


向score表插入記錄的INSERT語(yǔ)句如下：
INSERT INTO score VALUES(NULL,901, '計(jì)算機(jī)',98);
INSERT INTO score VALUES(NULL,901, '英語(yǔ)', 80);
INSERT INTO score VALUES(NULL,902, '計(jì)算機(jī)',65);
INSERT INTO score VALUES(NULL,902, '中文',88);
INSERT INTO score VALUES(NULL,903, '中文',95);
INSERT INTO score VALUES(NULL,904, '計(jì)算機(jī)',70);
INSERT INTO score VALUES(NULL,904, '英語(yǔ)',92);
INSERT INTO score VALUES(NULL,905, '英語(yǔ)',94);
INSERT INTO score VALUES(NULL,906, '計(jì)算機(jī)',90);
INSERT INTO score VALUES(NULL,906, '英語(yǔ)',85);

-- 3. 查詢 student 表的所有記錄
SELECT * FROM student;

-- 4. 查詢 student 表的第 2 條到 4 條記錄
SELECT * FROM student LIMIT 1, 3;

-- 5. 查詢所有學(xué)生的學(xué)號(hào)（id）、姓名（name）和院系（department）的信息
SELECT id, name, department FROM student;

-- 6. 查詢計(jì)算機(jī)系和英語(yǔ)系的學(xué)生的信息
SELECT * FROM student WHERE department IN ('計(jì)算機(jī)系', '英語(yǔ)系');

-- 7. 查詢年齡 18~22 歲的學(xué)生信息
SELECT * FROM student WHERE (2023 - birth) BETWEEN 18 AND 22;

-- 8. 查詢每個(gè)院系有多少人
SELECT department, COUNT(*) AS 人數(shù) FROM student GROUP BY department;

-- 9. 查詢每個(gè)科目的最高分
SELECT c_name, MAX(grade) AS 最高分 FROM score GROUP BY c_name;

-- 10. 查詢李四的考試科目和考試成績(jī)
SELECT c_name, grade FROM score WHERE stu_id = (SELECT id FROM student WHERE name = '李四');

-- 11. 用連接的方式查詢所有學(xué)生的信息和考試信息
SELECT student.*, score.c_name, score.grade FROM student JOIN score ON student.id = score.stu_id;

-- 12. 計(jì)算每個(gè)學(xué)生的總成績(jī)
SELECT stu_id, SUM(grade) AS 總成績(jī) FROM score GROUP BY stu_id;

-- 13. 計(jì)算每個(gè)考試科目的平均成績(jī)
SELECT c_name, AVG(grade) AS 平均成績(jī) FROM score GROUP BY c_name;

-- 14. 查詢計(jì)算機(jī)成績(jī)低于 95 的學(xué)生信息
SELECT student.* FROM student JOIN score ON student.id = score.stu_id WHERE score.c_name = '計(jì)算機(jī)' AND score.grade < 95;

-- 15. 查詢同時(shí)參加計(jì)算機(jī)和英語(yǔ)考試的學(xué)生的信息
SELECT student.* FROM student WHERE id IN (SELECT stu_id FROM score WHERE c_name = '計(jì)算機(jī)') AND id IN (SELECT stu_id FROM score WHERE c_name = '英語(yǔ)');

-- 16. 將計(jì)算機(jī)考試成績(jī)按從高到低進(jìn)行排序
SELECT * FROM score WHERE c_name = '計(jì)算機(jī)' ORDER BY grade DESC;

-- 17. 從 student 表和 score 表中查詢出學(xué)生的學(xué)號(hào)，然后合并查詢結(jié)果
SELECT id FROM student UNION SELECT stu_id FROM score;

-- 18. 查詢姓張或者姓王的同學(xué)的姓名、院系和考試科目及成績(jī)
SELECT student.name, student.department, score.c_name, score.grade FROM student JOIN score ON student.id = score.stu_id WHERE student.name LIKE