-- 部门表CREATE TABLE dept ( id INT PRIMARY KEY PRIMARY KEY, -- 部门id dname VARCHAR(50), -- 部门名称 loc VARCHAR(50) -- 部门所在地);-- 添加4个部门INSERT INTO dept(id,dname,loc) VALUES (10,‘教研部‘,‘北京‘),(20,‘学工部‘,‘上海‘),(30,‘销售部‘,‘广州‘),(40,‘财务部‘,‘深圳‘);-- 职务表，职务名称，职务描述CREATE TABLE job ( id INT PRIMARY KEY, jname VARCHAR(20), description VARCHAR(50));-- 添加4个职务INSERT INTO job (id, jname, description) VALUES(1, ‘董事长‘, ‘管理整个公司，接单‘),(2, ‘经理‘, ‘管理部门员工‘),(3, ‘销售员‘, ‘向客人推销产品‘),(4, ‘文员‘, ‘使用办公软件‘);-- 员工表CREATE TABLE emp ( id INT PRIMARY KEY, -- 员工id ename VARCHAR(50), -- 员工姓名 job_id INT, -- 职务id mgr INT , -- 上级领导 joindate DATE, -- 入职日期 salary DECIMAL(7,2), -- 工资 bonus DECIMAL(7,2), -- 奖金 dept_id INT, -- 所在部门编号 CONSTRAINT emp_jobid_ref_job_id_fk FOREIGN KEY (job_id) REFERENCES job (id), CONSTRAINT emp_deptid_ref_dept_id_fk FOREIGN KEY (dept_id) REFERENCES dept (id));-- 添加员工INSERT INTO emp(id,ename,job_id,mgr,joindate,salary,bonus,dept_id) VALUES (1001,‘孙悟空‘,4,1004,‘2000-12-17‘,‘8000.00‘,NULL,20),(1002,‘卢俊义‘,3,1006,‘2001-02-20‘,‘16000.00‘,‘3000.00‘,30),(1003,‘林冲‘,3,1006,‘2001-02-22‘,‘12500.00‘,‘5000.00‘,30),(1004,‘唐僧‘,2,1009,‘2001-04-02‘,‘29750.00‘,NULL,20),(1005,‘李逵‘,4,1006,‘2001-09-28‘,‘12500.00‘,‘14000.00‘,30),(1006,‘宋江‘,2,1009,‘2001-05-01‘,‘28500.00‘,NULL,30),(1007,‘刘备‘,2,1009,‘2001-09-01‘,‘24500.00‘,NULL,10),(1008,‘猪八戒‘,4,1004,‘2007-04-19‘,‘30000.00‘,NULL,20),(1009,‘罗贯中‘,1,NULL,‘2001-11-17‘,‘50000.00‘,NULL,10),(1010,‘吴用‘,3,1006,‘2001-09-08‘,‘15000.00‘,‘0.00‘,30),(1011,‘沙僧‘,4,1004,‘2007-05-23‘,‘11000.00‘,NULL,20),(1012,‘李逵‘,4,1006,‘2001-12-03‘,‘9500.00‘,NULL,30),(1013,‘小白龙‘,4,1004,‘2001-12-03‘,‘30000.00‘,NULL,20),(1014,‘关羽‘,4,1007,‘2002-01-23‘,‘13000.00‘,NULL,10);-- 工资等级表CREATE TABLE salarygrade ( grade INT PRIMARY KEY, -- 级别 losalary INT, -- 最低工资 hisalary INT -- 最高工资);-- 添加5个工资等级INSERT INTO salarygrade(grade,losalary,hisalary) VALUES (1,7000,12000),(2,12010,14000),(3,14010,20000),(4,20010,30000),(5,30010,99990);-- 需求：-- 1.查询所有员工信息。查询员工编号，员工姓名，工资，职务名称，职务描述SELECT emp.`id` AS ‘员工编号‘,-- 员工编号 emp.`ename` AS ‘员工姓名‘,-- 员工姓名 emp.`salary` AS ‘工资‘,-- 工资 job.`jname` AS ‘职务名称‘,-- 职务名称 job.`description` AS ‘职务描述‘-- 职务描述FROM emp,job -- 员工表 职务表WHERE emp.`job_id`=job.`id` -- 2.查询员工编号，员工姓名，工资，职务名称，职务描述，部门名称，部门位置SELECT emp.`id` AS ‘员工编号‘,-- 员工编号 emp.`ename` AS ‘员工姓名‘,-- 员工姓名 emp.`salary` AS ‘工资‘,-- 工资 job.`jname` AS ‘职务名称‘,-- 职务名称 job.`description` AS ‘职务描述‘,-- 职务描述 dept.`dname` AS ‘部门名称‘,-- 部门名称 dept.`loc` AS ‘部门位置‘-- 部门位置FROM emp,job,dept -- 员工表 职务表WHERE emp.`job_id` = job.`id` AND emp.`dept_id` = dept.`id` -- 3.查询员工姓名，工资，工资等级SELECT emp.ename AS ‘员工姓名‘, emp.salary AS ‘工资‘, salarygrade.grade ‘工资等级‘FROM emp,salarygradeWHERE emp.salary <= salarygrade.hisalary AND emp.salary >= salarygrade.losalary ;SELECT emp.ename AS ‘员工姓名‘, emp.salary AS ‘工资‘, salarygrade.grade AS ‘工资等级‘FROM emp,salarygradeWHERE emp.`salary`BETWEEN salarygrade.`losalary`AND salarygrade.`hisalary`;-- 4.查询员工姓名，工资，职务名称，职务描述，部门名称，部门位置，工资等级SELECT emp.`ename` AS ‘员工姓名‘,-- 员工姓名 emp.`salary` AS ‘工资‘,-- 工资 job.`jname` AS ‘职务名称‘,-- 职务名称 job.`description` AS ‘职务描述‘,-- 职务描述 dept.`dname` AS ‘部门名称‘,-- 部门名称 dept.`loc` AS ‘部门位置‘,-- 部门位置 salarygrade.`grade` AS ‘工资等级‘ -- 工资等级FROM emp,job,dept,salarygrade -- 员工表 职务表 部门表 工资登记表WHERE emp.`job_id` = job.`id`AND emp.`dept_id` = dept.`id`AND emp.`salary`BETWEEN salarygrade.`losalary`AND salarygrade.`hisalary`;-- 5.查询出部门编号、部门名称、部门位置、部门人数SELECT dept.`id` AS ‘部门编号‘,-- 部门编号 dept.`dname` AS ‘部门名称‘,-- 部门名称 dept.`loc` AS ‘部门位置‘,-- 部门位置 empt.dept_total AS ‘部门人数‘ -- 部门人数FROM dept,-- 部门表 (SELECT dept_id ,COUNT(id) AS ‘dept_total‘ FROM emp GROUP BY dept_id)AS empt -- 虚拟表WHERE dept.`id` = empt.`dept_id`; -- 6.查询所有员工的姓名及其直接上级的姓名,没有领导的员工也需要查询SELECT emp_1.`id` AS ‘员工编号‘, emp_1.`ename` AS ‘员工姓名‘, emp_2.`ename` AS ‘上级领导姓名‘FROM emp AS emp_1 LEFT JOIN emp AS emp_2 ON emp_1.`mgr` = emp_2.`id`;