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Re: How to add a datetime column for a 24 hour period

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Mike Arney (mikespcnet.net@gmail.com) writes:
> I need to SUM all Timestamp (in seconds) with a Topic of
> 'STG/A/CycleStart', a Payload of 1. 
> 
> Payload of 1 = Machine On 
> Payload of 0 = Machine Off 
> 
> I am trying to get amount of time that a Payload is = 1 over the last 24
> hours. 
> 

Here is a query. However, it is clear to how you want to handle the case
that the last row has Payload = 1. Should we count from that time until
"now", or is there something else? In the example I am assuming "now",
but you can change that as you see fit.

LEAD returns the next row in the result set as defined by the OVER clause.

; WITH ontimes AS (
    SELECT Topic, 
           CASE WHEN Payload = 1
                THEN datediff(ss, Timestamp,
                                  LEAD(Timestamp, 1, sysutcdatetime()) 
                                     OVER (PARTITION BY Topic ORDER BY Timestamp))
                ELSE 0
           END AS ontime
    FROM  MQTTData
)
SELECT Topic, SUM(ontime) 
FROM   ontimes
GROUP  BY Topic





-- 
Erland Sommarskog, Stockholm, esquel@sommarskog.se

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How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-10-23 11:42 -0700
  Re: How to add a datetime column for a 24 hour period Erland Sommarskog <esquel@sommarskog.se> - 2017-10-23 23:51 +0200
    Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-10-24 05:10 -0700
      Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-10-24 05:12 -0700
    Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-10-24 05:38 -0700
      Re: How to add a datetime column for a 24 hour period Erland Sommarskog <esquel@sommarskog.se> - 2017-10-24 20:49 +0200
        Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-10-25 04:57 -0700
          Re: How to add a datetime column for a 24 hour period Erland Sommarskog <esquel@sommarskog.se> - 2017-10-26 20:58 +0200
            Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2017-11-02 09:54 -0700
              Re: How to add a datetime column for a 24 hour period mikespcnet.net@gmail.com - 2018-05-08 08:21 -0700
                Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2018-05-08 08:35 -0700
                Re: How to add a datetime column for a 24 hour period Erland Sommarskog <esquel@sommarskog.se> - 2018-05-08 19:48 +0200
                Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2018-05-09 06:31 -0700
                Re: How to add a datetime column for a 24 hour period Mike Arney <mikespcnet.net@gmail.com> - 2018-05-09 06:34 -0700
                Re: How to add a datetime column for a 24 hour period Erland Sommarskog <esquel@sommarskog.se> - 2018-05-09 23:08 +0200

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