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题解 | #获取每个部门中当前员工薪水最高的相关信息#

select dept_no, s.emp_no, salary as max_Salary from salaries s join dept_emp de on s.emp_no = de.emp_no where (dept_no, salary) in ( select dept_n...

2023-02-21

0 135

题解 | #查找字符串中逗号出现的次数#

SELECT id, LENGTH(REGEXP_REPLACE(string, '[A-Za-z0-9]', '')) AS cnt FROM strings

Mysql

2022-09-06

0 168

题解 | #回答过教育类问题的用户里回答过职场类问题的人数#

SELECT COUNT(DISTINCT author_id) AS num FROM ( -- 筛选出既回答过教育类又回答过职场类问题的用户 ...

Mysql

2022-07-15

0 149

题解 | #某乎问答单日回答问题数大于等于3个的所有用户#

SELECT answer_date, author_id, COUNT(issue_id) AS answer_cnt FROM answer_tb WHERE MONTH(answer_date) = '11' GROUP BY answer_date, author_...

Mysql

2022-07-15

0 185

题解 | #牛客直播各科目出勤率#

SELECT course_id, course_name, ROUND(attend_cnt * 100 / sign_cnt, 2) AS 'attend_rate(%)' FROM ( SELECT course_id, &...

Mysql

2022-07-10

0 143

题解 | #牛客直播各科目平均观看时长#

SELECT course_name, ROUND( AVG(TIMESTAMPDIFF(MINUTE, in_datetime, out_datetime)), &nbs...

Mysql

2022-07-10

0 154

题解 | #获取所有员工当前的manager#

SELECT d_e.emp_no AS emp_no, d_m.emp_no AS manager FROM dept_emp d_e LEFT&nbs...

Mysql

2022-07-09

1 123

题解 | #牛客直播转换率#

SELECT course_id, course_name, ROUND(COUNT(DISTINCT IF(if_sign = 1, user_id, NULL)) / COUNT(DISTINCT IF(if_vw = 1, user_id, NULL)) * 100, 2) AS ...

Mysql

2022-06-22

0 186

题解 | #某宝店铺连续2天及以上购物的用户及其对应的天数#

SELECT user_id, MAX(diff_rank) AS days_count FROM ( SELECT user_id, DATE_SUB(sales_date, INTERVAL date_rank DAY) AS dt, DENSE_...

Mysql

2022-06-22

0 185

题解 | #某宝店铺动销率与售罄率#

SELECT style_id, ROUND(IFNULL(total_sales_num, 0) / (total_inventory - total_sales_num) * 100, 2) AS 'pin_rate(%)', ROUND(GVM / inventory_valu...

Mysql

2022-06-20

0 151