寫在前面 今天繼續前面的20題之後的練習,數據都是一樣的,可以直接使用,來看看你的sql功底降了沒。 基礎20題 #1.查詢每個員⼯的姓名、郵箱、職位名稱以及所在部⻔名稱。 SELECT CONCAT(last_name,first_name) as 姓名, email, job_title, de ...
寫在前面
今天繼續前面的20題之後的練習,數據都是一樣的,可以直接使用,來看看你的sql功底降了沒。
基礎20題
#1.查詢每個員⼯的姓名、郵箱、職位名稱以及所在部⻔名稱。
SELECT
CONCAT(last_name,first_name) as 姓名,
email,
job_title,
department_name
FROM
employees e
JOIN departments d ON e.department_id=d.department_id
JOIN jobs j ON e.job_id = j.job_id ;
#2.查詢⽉薪最⾼的員⼯的姓名、職位名稱以及⽉薪。
SELECT
CONCAT(last_name,first_name) as 姓名,
job_title,
salary
FROM
employees e
JOIN jobs j on e.job_id = j.job_id
WHERE salary = (SELECT MAX(salary) FROM employees);
#3.查詢每個部⻔的平均⽉薪。
#註:如果某一部門沒有員工不會顯示
SELECT
department_name,
AVG(salary)
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
GROUP BY
department_name;
#4.查詢部⻔中員⼯⽉薪⾼於5000的所有員⼯的姓名、⽉薪以及所在部⻔名稱。
SELECT
CONCAT(last_name,first_name) as 姓名,
salary,
department_name
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
WHERE
salary > 5000;
#5.查詢獎⾦率最⾼的員⼯的姓名、職位名稱以及獎⾦率。
SELECT
CONCAT(last_name,first_name) as 姓名,
job_title,
commission_pct
FROM
employees e
JOIN jobs j ON e.job_id = j.job_id
WHERE
commission_pct = (SELECT MAX(commission_pct) FROM employees);
#6.查詢每個職位的最⾼⽉薪和最低⽉薪。
SELECT
job_title,
MAX(salary),
MIN(salary)
FROM
employees e
JOIN jobs j ON e.job_id = j.job_id
GROUP BY
job_title;
#7.查詢⼊職時間早於2000年的所有員⼯的姓名、⼊職⽇期以及職位名稱。
SELECT
CONCAT(last_name,first_name) as 姓名,
hiredate,
job_title
FROM
employees e
JOIN jobs j on e.job_id = j.job_id
WHERE
YEAR(hiredate) < 2000;
#8.查詢每個部⻔的員⼯⼈數。
SELECT
COUNT(*) as 人數,
department_name
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
GROUP BY
department_name;
#9.查詢在每個部⻔中⽉薪最⾼的員⼯的姓名、⽉薪以及部⻔名稱。
#註:在使用in時可以使用()將需要的列括起來查詢
SELECT
CONCAT(e.last_name,e.first_name) as 姓名,
e.salary,
d.department_name
FROM
employees e JOIN departments d ON e.department_id = d.department_id
WHERE
(e.salary,d.department_id) in (
SELECT MAX(salary),department_id FROM employees GROUP BY department_id);
#10.查詢⽉薪超過部⻔平均⽉薪的員⼯的姓名、⽉薪以及所在部⻔名稱。
SELECT
CONCAT( e1.last_name, e1.first_name ) AS 姓名,
e1.salary,
d.department_name
FROM
employees e1
JOIN departments d ON e1.department_id = d.department_id
WHERE
e1.salary > ( SELECT AVG( e2.salary ) FROM employees e2 WHERE e1.department_id = e2.department_id);
#11.查詢每個職位的員⼯⼈數。
SELECT
COUNT(*) as 人數,
job_title
FROM
employees e
JOIN jobs j ON e.job_id = j.job_id
GROUP BY
job_title;
#12.查詢每個部⻔的最⾼⽉薪和最低⽉薪。
SELECT
department_name,
MAX(salary),
MIN(salary)
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
GROUP BY
department_name;
#13.查詢每個員⼯的姓名、郵箱、職位名稱以及他們的上級領導的姓名。
SELECT
CONCAT(e1.last_name,e1.first_name) as 姓名,
e1.email,
j.job_title,
CONCAT(e2.last_name,e2.first_name) as 上級領導
FROM
employees e1
JOIN employees e2 ON e1.manager_id = e2.employee_id
JOIN jobs j ON e1.job_id = j.job_id;
#14.查詢每個部⻔的員⼯平均獎⾦率。
SELECT
department_name,
AVG(commission_pct) as 平均獎金率
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
GROUP BY
department_name;
#15.查詢每個城市的員⼯⼈數。
SELECT
COUNT(*) as 人數,
city
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
JOIN locations l ON d.location_id = l.location_id
GROUP BY
city;
#16.查詢每個部⻔的職位種類數。
#註:使用distinct可以去重算種類數
SELECT
COUNT(DISTINCT job_id) as 種類數,
department_name
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
GROUP BY
department_name;
#17.查詢⼯資⾼於其職位平均⼯資的員⼯姓名、職位名稱以及⽉薪。
SELECT
CONCAT(e1.last_name, e1.first_name ) AS 姓名,
j.job_title,
e1.salary
FROM
employees e1
JOIN jobs j ON e1.job_id = j.job_id
WHERE
e1.salary > (SELECT AVG(e2.salary) FROM employees e2 WHERE e1.job_id = e2.job_id);
#18.查詢每個國家的員⼯⼈數。
SELECT
COUNT(DISTINCT employee_id) as 人數,
country_id
FROM
employees e
JOIN departments d ON e.department_id = d.department_id
JOIN locations l ON d.location_id = l.location_id
GROUP BY
country_id;
#19.查詢沒有領導的員⼯的姓名以及職位名稱。
SELECT
CONCAT( last_name, first_name ) AS 姓名,
job_title
FROM
employees e
JOIN jobs j ON e.job_id = j.job_id
WHERE
manager_id is null ;
#20.查詢job_id為"IT_PROG"的員⼯的姓名、職位名稱以及⽉薪。
SELECT
CONCAT( last_name, first_name ) AS 姓名,
job_title,
salary
FROM
employees e
JOIN jobs j ON e.job_id = j.job_id
WHERE
e.job_id = 'IT_PROG';
好了,今天的分享結束了,答案僅供參考不代表最終答案,如果有更好的方法,歡迎在底下留言評論!