准备进厂的芹菜很伟大

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题解 | 查询下订单用户访问次数？

SELECT o.user_id,COUNT(DISTINCT v.visit_time) AS visit_numsFROM order_tb AS o JOIN visit_tb AS v ON o.user_id = v.user_idWHERE DATE(o.order_time) = '...

2025-04-06

0 38

题解 | 统计用户从访问到下单的转化率

SELECT a.date, CONCAT (ROUND(od / nd * 100, 1), '%') AS cr FROM ( SELECT DATE (o.order_time) AS date, COUN...

2025-04-06

0 31

题解 | 查询连续登陆的用户

SELECT user_id FROM ( SELECT r.user_id, DATE ( LEAD (log_time, 2, '1990-01-01') over ( ...

2025-03-23

0 49

题解 | 统计各岗位员工平均工作时长

SELECT s.post, ROUND( AVG( TIMESTAMPDIFF (SECOND, a.first_clockin, a.last_clockin) ) / 3600, 3 ) AS wo...

2025-03-23

0 46

题解 | 每个商品的销售总额

SELECT name AS product_name, SUM(quantity) as total_sales, ROW_NUMBER() OVER ( PARTITION BY p.category ORDER B...

2025-03-19

0 34

题解 | 推荐内容准确的用户平均评分

SELECT ROUND( SUM(DISTINCT u.score) / COUNT(DISTINCT u.user_id), 3 ) AS avg_score FROM recommend_tb as r JOIN user_act...

2025-03-19

0 40

题解 | 查询培训指定课程的员工信息

SELECT s.staff_id, s.staff_name FROM staff_tb as s JOIN cultivate_tb AS c ON s.staff_id = c.staff_id WHERE c.course LIKE '%3' ORDE...

2025-03-19

0 36

题解 | 统计所有课程参加培训人次

SELECT ROUND( SUM( LENGTH (REPLACE (course, ',', '')) / LENGTH ('course1') ), 0 ) as staff_nums FROM c...

2025-03-19

0 31