题解 | 统计所有课程参加培训人次
统计所有课程参加培训人次
https://www.nowcoder.com/practice/98aad5807cf34a3b960cc8a70ce03f53
WITH RECURSIVE nums AS (
SELECT 1 AS n
UNION ALL
SELECT n + 1 FROM nums WHERE n < 3
)
SELECT COUNT(*) AS staff_nums
FROM cultivate_tb c
JOIN nums ON nums.n <= LENGTH(c.course) - LENGTH(REPLACE(c.course, ',', '')) + 1
WHERE c.course IS NOT NULL;
