题解 | #异常的邮件概率#
异常的邮件概率
https://www.nowcoder.com/practice/d6dd656483b545159d3aa89b4c26004e
SELECT e.date
,ROUND(SUM(IF(e.type="no_completed",1,0))/COUNT(*),3)
FROM email e
LEFT JOIN user u1 ON e.send_id=u1.id
LEFT JOIN user u2 ON e.send_id=u2.id
WHERE u1.is_blacklist=0
AND u2.is_blacklist=0
GROUP BY e.date
ORDER BY e.date
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