SQL Server 按时间间隔提取数据开展数据采样

Select Ana1,RdDate,RdTime,cast(convert(varchar,RdDate,112)+' '+convert(varchar,RdTime,108) as datetime) as time,t.interval FROM (SELECT Ana1,RdDate,RdTime, datediff (mi,cast(convert(varchar,RdDate,112)+' '+convert(varchar,RdTime,108) as datetime), GETDATE()) AS interval  FROM Records ) AS t WHERE t.interval%10 = 0  //获取间隔十分钟的数据，但是获取之后分钟相同的还会有重复，仍需进一步处理