MySQL基础练习20题，看看你的sql基础man不man

大龙猫 · 发表于 2024-7-26 09:46:35

数据获取

表的数据信息(sql文件)放在这个链接里了，提取码：52xz，需要的自行提取。数据来自网上的练习，已经给小伙伴们总结好了。
https://pan.baidu.com/s/11YMWaXtZb9K60cpOuYTwag
将数据导入到mysql中

大家可以直接在navicat运行该脚本，就可以直接导入数据了，如果遇到问题很可能是编码问题，改一下数据库的编码为gb2312，如图：

基础20题

点击新建查询就可以写我们的mysql基础20题了。

#(1)查询和Zlotkey相同部门的员工姓名和工资
SELECT
last_name,
salary
FROM
employees
WHERE
department_id = ( SELECT department_id from employees WHERE last_name = "Zlotkey" );
#(2)查询工资比公司平均工资高的员工的员工号，姓名和工资。
SELECT
employee_id,
last_name,
salary
FROM
employees
WHERE
salary > (SELECT AVG(salary) FROM employees);
#(3)选择工资大于所有JOB_ID = SA_MAN 的员工的工资的员工的last_name, job_id, salary
SELECT
last_name,
job_id,
salary
FROM
employees
WHERE
salary > ( SELECT max( salary ) FROM employees WHERE job_id = "SA_MAN" );
#(4)查询和姓名中包含字母u的员工在相同部门的员工的员工号和姓名
SELECT
employee_id,
last_name
FROM
employees
WHERE
department_id IN (
SELECT DISTINCT
( department_id )
FROM
employees
WHERE
last_name LIKE "%u%")
#(5)查询在部门的location_id为1700的部门工作的员工的员工号
SELECT
employee_id
FROM
employees
WHERE
department_id IN ( SELECT department_id FROM departments WHERE location_id = 1700 );
#(6)查询管理者是King的员工姓名和工资
SELECT
last_name,
salary
FROM
employees
WHERE
manager_id IN ( SELECT employee_id FROM employees WHERE last_name = "K_ing" );
#(7)查询工资最低的员工信息: last_name, salary
SELECT
last_name,
salary
FROM
employees
WHERE
salary = ( SELECT min( salary ) FROM employees );
#(8)查询平均工资最低的部门信息
SELECT
b.department_id,
d.department_name,
d.manager_id,
d.location_id
FROM
departments d
JOIN (
SELECT
department_id,
AVG( salary ) AS avg_salary
FROM
employees
GROUP BY
department_id
HAVING
avg_salary IN (
SELECT
MIN( a.avg_salary )
FROM (
SELECT
department_id,
AVG( salary ) AS avg_salary
FROM employees
GROUP BY department_id
) AS a
)
) AS b
ON d.department_id = b.department_id;
#(9)查询平均工资最低的部门信息和该部门的平均工资（相关子查询）
SELECT
b.department_id,
d.department_name,
d.manager_id,
d.location_id,
b.avg_salary
FROM
departments d
JOIN (
SELECT
department_id,
AVG( salary ) AS avg_salary
FROM
employees
GROUP BY
department_id
HAVING
avg_salary IN (
SELECT
MIN( a.avg_salary )
FROM (
SELECT
department_id,
AVG( salary ) AS avg_salary
FROM employees
GROUP BY department_id
) AS a
)
) AS b
ON d.department_id = b.department_id;
#(10)查询平均工资最高的 job 信息
SELECT
b.job_id,
j.job_title,
j.min_salary,
j.max_salary
FROM
jobs j
JOIN
(
SELECT
job_id ,
AVG(salary) AS avg_salary
FROM
employees
GROUP BY
job_id
HAVING
avg_salary in
(
SELECT
MAX(a.avg_salary)
FROM
(
SELECT
job_id,
AVG( salary ) AS avg_salary
FROM
employees
GROUP BY
job_id
) as a
)
)as b
ON j.job_id = b.job_id;
#(11)查询平均工资高于公司平均工资的部门有哪些?
SELECT
department_id,
AVG(salary) as avg_salary
FROM
employees
WHERE
department_id is not null
GROUP BY
department_id
HAVING
avg_salary > (
SELECT
AVG(salary)
FROM
employees );
#(12)查询出公司中所有 manager 的详细信息
SELECT
*
FROM
employees
WHERE
employee_id in
(
SELECT
DISTINCT manager_id
FROM
employees);
#(13)各个部门中最高工资中最低的那个部门的最低工资是多少?
SELECT
MAX(salary) as max_salary
FROM
employees
WHERE
department_id is not null
GROUP BY
department_id
ORDER BY
max_salary
LIMIT 0,1;
#(14)查询平均工资最高的部门的 manager 的详细信息: last_name, department_id, email, salary
SELECT
last_name,
department_id,
email,
salary
FROM
employees
WHERE
employee_id in
(
SELECT
DISTINCT manager_id
FROM
employees
WHERE
department_id = (
SELECT
department_id
FROM
employees
GROUP BY
department_id
HAVING
AVG( salary ) IN (
SELECT
MAX( a.avg_salary )
FROM
(
SELECT
department_id,
AVG( salary ) AS avg_salary
FROM
employees
GROUP BY
department_id
) AS a
)
)
);
#(15)查询部门的部门号，其中不包括job_id是"ST_CLERK"的部门号
SELECT
department_id
FROM
employees
WHERE
job_id NOT IN (
SELECT
job_id
FROM
employees
WHERE
job_id = "ST_CLERK");
#(16)选择所有没有管理者的员工的last_name
SELECT
last_name
FROM
employees
WHERE
manager_id is null;
#(17)查询员工号、姓名、雇用时间、工资，其中员工的管理者为 ‘De Haan’
SELECT
employee_id,
last_name,
hiredate,
salary
FROM
employees
WHERE
manager_id = (SELECT
employee_id
FROM
employees
WHERE
last_name = "De Haan");
#(18)查询各部门中工资比本部门平均工资高的员工的员工号, 姓名和工资（相关子查询）
SELECT employee_id,last_name,salary,department_id
FROM employees e1
WHERE salary > (
# 查询某员工所在部门的平均
SELECT AVG(salary)
FROM employees e2
WHERE e2.department_id = e1.`department_id`);
#(19)查询每个部门下的部门人数大于 5 的部门名称（相关子查询）
SELECT
department_name
FROM
departments
WHERE
department_id in (
SELECT
department_id
FROM
employees
GROUP BY
department_id
HAVING
COUNT(*) > 5);
#(20)查询每个国家下的部门个数大于 2 的国家编号（相关子查询）
SELECT
country_id
FROM
locations
WHERE
location_id in (
SELECT
location_id
FROM
departments
GROUP BY
location_id
HAVING
COUNT(*) > 2);
好了，今天的分享已经结束了，以后我还会多多更新这些对于大数据技术较为基础的相关分享，希望大家能共同进步，一起加油！

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来源:https://www.cnblogs.com/cjybigdatablog/p/18324077
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MySQL基础练习20题，看看你的sql基础man不man

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