数据库基础练习4

准备

create table dept (dept1 int ,dept_name varchar(11)) charset=utf8;
create table emp (sid int ,name varchar(11),age int,worktime_start date,incoming int,dept2 int) charset=utf8;

     insert into dept values
    (101,'财务'),
    (102,'销售'),
    (103,'IT技术'),
    (104,'行政');

    INSERT INTO emp VALUES
    (1789, '张三', 35, '1980-01-01', 4000, 101),
    (1674, '李四', 32, '1983-04-01', 3500, 101),
    (1776, '王五', 24, '1990-07-01', 2000, 101),
    (1568, '赵六', 57, '1970-10-11', 7500, 102),
    (1564, '荣七', 64, '1963-10-11', 8500, 102),
    (1879, '牛八', 55, '1971-10-20', 7300, 103),
    (1668, '钱九', 64, '1963-05-04', 8000, 102),
    (1724, '武十', 22, '2023-05-08', 1500, 103),
    (1770, '孙二', 65, '1986-08-12', 9500, 101),
    (18400, '苟一', 65, '1986-08-12', 1500, 101);

练习

1.找出销售部门中年纪最大的员工的姓名

SELECT name 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = '销售') 
ORDER BY age DESC 
LIMIT 2;

2.求财务部门最低工资的员工姓名

SELECT name 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = '财务') 
ORDER BY incoming ASC 
LIMIT 1;

3.列出每个部门收入总和高于9000的部门名称

SELECT d.dept_name 
FROM dept d 
JOIN emp e ON d.dept1 = e.dept2 
GROUP BY d.dept_name 
HAVING SUM(e.incoming) > 9000;

4.求工资在7500到8500元之间，年龄最大的人的姓名及部门

SELECT e.name, d.dept_name 
FROM emp e 
JOIN dept d ON e.dept2 = d.dept1 
WHERE e.incoming BETWEEN 7500 AND 8500 
ORDER BY e.age DESC 
LIMIT 1;

5.找出销售部门收入最低的员工入职时间

SELECT worktime_start 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = '销售') 
ORDER BY incoming ASC 
LIMIT 1;

6.财务部门收入超过2000元的员工姓名

SELECT name 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = '财务') 
AND incoming > 2000;

7.列出每个部门的平均收入及部门名称

SELECT d.dept_name, AVG(e.incoming) AS avg_income 
FROM emp e 
JOIN dept d ON e.dept2 = d.dept1 
GROUP BY d.dept_name;

8.IT技术部入职员工的员工号

SELECT sid 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = 'IT技术');

9.财务部门的收入总和；

SELECT SUM(incoming) AS total_income 
FROM emp 
WHERE dept2 = (SELECT dept1 FROM dept WHERE dept_name = '财务');

10.找出哪个部门还没有员工入职；

SELECT dept_name 
FROM dept 
WHERE dept1 NOT IN (SELECT DISTINCT dept2 FROM emp);

11.列出部门员工收入大于7000的部门编号，部门名称；

SELECT d.dept1, d.dept_name 
FROM dept d 
JOIN emp e ON d.dept1 = e.dept2 
GROUP BY d.dept1, d.dept_name
HAVING MAX(e.incoming) > 7000;

12.列出每一个部门的员工总收入及部门名称；

SELECT d.dept_name, SUM(e.incoming) AS total_income 
FROM emp e 
JOIN dept d ON e.dept2 = d.dept1 
GROUP BY d.dept_name;

13.列出每一个部门中年纪最大的员工姓名，部门名称；

SELECT e.name, d.dept_name 
FROM emp e
JOIN dept d ON e.dept2 = d.dept1
WHERE e.age = (
    SELECT MAX(sub_e.age)
    FROM emp sub_e
    WHERE sub_e.dept2 = e.dept2
)
ORDER BY e.age DESC;

14.求李四的收入及部门名称

SELECT e.incoming, 
       (SELECT d.dept_name FROM dept d WHERE d.dept1 = e.dept2) AS dept_name
FROM emp e
WHERE e.name = '李四';

15.列出每个部门中收入最高的员工姓名，部门名称，收入，并按照收入降序

SELECT e.name, d.dept_name, e.incoming 
FROM emp e 
JOIN dept d ON e.dept2 = d.dept1 
WHERE e.incoming = (
    SELECT MAX(incoming) 
    FROM emp 
    WHERE dept2 = e.dept2
)
ORDER BY e.incoming DESC;