Mysql根据列值删除重复的行，但保留最新的行

Question

我有一个包含3个字段的表（phonecall，calldate，checked），我想通过phonecall列值删除重复的行，但不是最新的。

在这种情况下，我想从该表的第一行中删除2行。

由于

Answer 1

像这样：

delete A from TableX A
  left join TableX B
    on B.CallDate>A.CallDate and B.PhoneCall=A.PhoneCall
 where B.PhoneCall is not null

Answer 2

这可能有效：

delete callLog
from callLog
  inner join (
     select max(CallDate) as lastCallDate, PhoneCall
     from callLog
     group by PhoneCall
     having count(*) > 1) duplic on duplic.PhoneCall = callLog.PhoneCall
where callLog.CallDate < duplic.lastCallDate;