以半個小時爲間隔計算電話號碼

Question

我試圖按半小時間隔計算電話計數。 無法弄清楚。通過不同的時間間隔來聚合

select 
     count(call_id) as '#Calls', 
     1/2 h(date_time) as 'Call_Interval' 
from My_Table 

Answer 1

的一種方法是用DATEADD和DATEDIFF：

SELECT 
     COUNT(*) as '#Calls', 
     DATEADD(minute, (DATEDIFF(minute, '', date_time)/30) * 30, '') as Call_Interval 
FROM dbo.My_Table 
GROUP BY DATEADD(minute, (DATEDIFF(minute, '', date_time)/30) * 30, '') 
ORDER BY Call_Interval;