题解 | 截取出年龄
截取出年龄
https://www.nowcoder.com/practice/b8d8a87fe1fc415c96f355dc62bdd12f
SELECT
age,
count(device_id) as number
from
(
SELECT
device_id,
SUBSTRING_INDEX(SUBSTRING_INDEX(profile, ',', 3), ',', -1) AS age
FROM
user_submit
) t
group by
age
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