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sql server 分组并取每组的时间最大值 SELECT TOP 100 PERCENT a.Device_ID, a.Device_Code, b.Device_Name, MAX (a.StartTime) StartTime, FROM Test1 a LEFT JOIN Test2 b ON a.Device_ID = b.Device_ID WHERE 1 = 1 AND a.Device_ID= '564D6E83' AND a.Device_Code IS NOT NULL