将时间从{yyyy-mm-dd hh：mm：ss}转换为{yyyy-mm-dd hh}

Question

I am trying to extract data from a large SQL DB on hourly basis. The following query is giving me a grouping on minute basis. I wish to group by the data on hourly basis.

select CONVERT(VARCHAR(20), t.counterTime, 100) as [Time],
    t.instanceName
from table as t
WHERE t.counterId= @counterId
and t.counterTime >=  @startTime
and t.counterTime <  @endTime
group by t.instanceName, CONVERT(VARCHAR(20), t.counterTime, 100)

The documentation also does not provide any such option. Any ideas?

Answer 1

Try like this,

--SQL Server 2012
SELECT FORMAT(t.counterTime, 'yyyy-MM-dd HH') AS [Time]
    ,t.instanceName
FROM TABLE AS t
WHERE t.counterId = @counterId
    AND t.counterTime >= @startTime
    AND t.counterTime < @endTime
GROUP BY t.instanceName
    ,FORMAT(t.counterTime, 'yyyy-MM-dd HH')

--for earlier versions
SELECT CONVERT(CHAR(13), t.counterTime, 120) AS [Time]
    ,t.instanceName
FROM TABLE AS t
WHERE t.counterId = @counterId
    AND t.counterTime >= @startTime
    AND t.counterTime < @endTime
GROUP BY t.instanceName
    ,CONVERT(CHAR(13), t.counterTime, 120)

Note: Format would be perfoming slower.

Answer 2

您可以使用以下子字符串：

select substring(field,1,4) + '-'+ substring(field,6,2) +'-'+ substring(field,7,2)+' '+ substring(field,9,2)  from dbo.youtable 

Answer 3

Try this

select datepart(hour,t.counterTime) as [Time],
    t.instanceName
from table as t
WHERE t.counterId= @counterId
and t.counterTime >=  @startTime
and t.counterTime <  @endTime
group by t.instanceName, datepart(hour,t.counterTime)