[英]How can I take the ids of the registrations with the highest temperature of each day (on a specified period of time)?
Considering I have more than 30 registers/day for that temperature. 考虑到我每天有超过30个寄存器用于该温度。
I want one registration for each day, for example: 我想每天进行一次注册,例如:
date: 2015-12-10 12:02 id: 2341 tempa: 54 (which is the highest on that day)
date: 2015-12-09 15:04 id 1923 tempa: 32 (which is the highest on that day)
and so on.... 等等....
您可以使用max和group by
select max(TempA) from your_table group by day_column
select id from temperatures where TempA=(select max(TempA) from temperatures )
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