爱吃菜叶的猫

分类

评论(2) 题解(61)

/ 注册

全部文章（共65篇）

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

0 155

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

0 192

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

0 150

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

0 160

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

1 124

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

0 192

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

0 192

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

0 155

题解 | #某宝店铺折扣率#

SELECT ROUND(SUM(sales_price) / SUM(t_tag_price) * 100, 2) AS 'discount_rate(%)' FROM ( SELECT item_id, sales_num * tag_price AS t_tag_pr...

Mysql

2022-06-20

0 181