Mysql 本月和上月两个日期时间之间的平均时间

我们有一个表，有两个字段tkTimeOpen和tktimecolled。我们需要找到这个月和上个月的平均等待时间。我一直无法获得正确的SQL查询来提取我需要的内容

这是记录日期和时间的方式；2017-01-25 10:35

这个月的平均值

SELECT SUM(DATEDIFF(MINUTE,tkTimeOpen,tkTimeClose)) * 1.0 
           / (SELECT COUNT(*) * 1.0 FROM e_ticket)
FROM e_ticket
WHERE YEAR(tkTimeOpen) = YEAR(CURRENT_DATE - INTERVAL 1 MONTH) AND MONTH(tkTimeOpen) = MONTH(CURRENT_DATE - INTERVAL 0 MONTH)

上个月的平均值

SELECT SUM(DATEDIFF(MINUTE,tkTimeOpen,tkTimeClose)) * 1.0 
           / (SELECT COUNT(*) * 1.0 FROM e_ticket)
FROM e_ticket
WHERE YEAR(tkTimeOpen) = YEAR(CURRENT_DATE - INTERVAL 1 MONTH) AND MONTH(tkTimeOpen) = MONTH(CURRENT_DATE - INTERVAL 1 MONTH)

我尝试了很多变化，但都没有达到预期的效果。 如果有人能帮忙，那就太好了

多谢各位

您可以使用的一个函数是

TIMESTAMPDIFF

——而不是

DATEDIFF

您可以使用

AVG（）

而不是

SUM（）/COUNT（）

---

这将为您提供上个月和本月的平均分钟数：

SELECT AVG(TIMESTAMPDIFF(MINUTE, tkTimeOpen, tkTimeClose)) 
FROM e_ticket 
WHERE tkTimeOpen >= DATE_ADD(LAST_DAY(DATE_SUB(NOW(), INTERVAL 2 MONTH)), INTERVAL 1 DAY);

如果您仍然需要单独获得平均值，您可以保持WHERE子句与您拥有的相似

本月：

SELECT AVG(TIMESTAMPDIFF(MINUTE, tkTimeOpen, tkTimeClose)) 
FROM e_ticket 
WHERE YEAR(tkTimeOpen) = YEAR(NOW()) AND MONTH(tkTimeOpen) = MONTH(NOW());

上个月：

SELECT AVG(TIMESTAMPDIFF(MINUTE, tkTimeOpen, tkTimeClose)) 
FROM e_ticket 
WHERE YEAR(tkTimeOpen) = YEAR(NOW() - INTERVAL 1 MONTH) AND MONTH(tkTimeOpen) = MONTH(NOW() - INTERVAL 1 MONTH);

SELECT AVG(TIMESTAMPDIFF(MINUTE, tkTimeOpen, tkTimeClose)) 
FROM e_ticket 
WHERE YEAR(tkTimeOpen) = YEAR(NOW() - INTERVAL 1 MONTH) AND MONTH(tkTimeOpen) = MONTH(NOW() - INTERVAL 1 MONTH);