如何在间隔 30 秒的时间戳之间选择数据

Question

美好的一天。我有两张桌子，TableA 和 TableB。 TableA 有一个开始和停止时间。 TableB 有带时间戳的数据。我试图将TableA 分隔成一个更大的表，间隔为 30 秒，并让TableBs 数据连接到开始时间和停止时间之间最近的 30 秒时间戳。

如何有效地创建一个以 30 秒为间隔的表格，并根据最近的时间戳连接另一个表格数据？任何帮助深表感谢。

表A

pkid     dateEntered
    1       2018-10-09 14:18:34.823
    2       2018-10-09 14:28:30.963

表B

processVal  dateEntered
55.2431   2018-10-09 14:18:34.953
55.2158   2018-10-09 14:19:04.960
54.7972   2018-10-09 14:19:34.963
54.7933   2018-10-09 14:20:04.963
54.7661   2018-10-09 14:20:34.967
54.7427   2018-10-09 14:21:04.967
54.7193   2018-10-09 14:21:34.970
54.6921   2018-10-09 14:22:04.970
54.6668   2018-10-09 14:22:34.973
54.6375   2018-10-09 14:23:04.973
54.6142   2018-10-09 14:23:34.977
54.585    2018-10-09 14:24:04.977
54.5597   2018-10-09 14:24:34.980
54.5363   2018-10-09 14:25:04.980
54.509    2018-10-09 14:25:34.983
54.4857   2018-10-09 14:26:04.987
54.4584   2018-10-09 14:26:34.987
54.435    2018-10-09 14:27:04.987
54.4097   2018-10-09 14:27:34.990
54.3825   2018-10-09 14:28:04.990

期望的结果

55.2431   2018-10-09 14:18:30.000
55.2158   2018-10-09 14:19:00.000
54.7972   2018-10-09 14:19:30.000
54.7933   2018-10-09 14:20:00.000
54.7661   2018-10-09 14:20:30.000
54.7427   2018-10-09 14:21:00.000
54.7193   2018-10-09 14:21:30.000
54.6921   2018-10-09 14:22:00.000
54.6668   2018-10-09 14:22:30.000
54.6375   2018-10-09 14:23:00.000
54.6142   2018-10-09 14:23:30.000
54.585    2018-10-09 14:24:00.000
54.5597   2018-10-09 14:24:30.000
54.5363   2018-10-09 14:25:00.000
54.509    2018-10-09 14:25:30.000
54.4857   2018-10-09 14:26:00.000
54.4584   2018-10-09 14:26:30.000
54.435    2018-10-09 14:27:00.000
54.4097   2018-10-09 14:27:30.000
54.3825   2018-10-09 14:28:00.000

Answer 1

您能否尝试使用 CASE 语句和 DATEADD() 函数执行 SQL 选择

declare @startdate datetime = '2018-10-09 14:18:34.823'
declare @enddate datetime = '2018-10-09 14:28:30.963'

select 
    case when DATEPART(ss, DateEntered) < 30 
    then 
        dateadd(ms,-1 * (DATEPART(ms, DateEntered) ), dateadd(ss,-1 * (DATEPART(ss, DateEntered) ),DateEntered))
    else 
        dateadd(ms,-1 * (DATEPART(ms, DateEntered) ), dateadd(ss,60 -1 * (DATEPART(ss, DateEntered) ),DateEntered)) 
    end
from TableB
where
DateEntered between @startdate and @enddate