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From:Johan De Meersman Date:April 27 2010 1:56pm
Subject:Re: Query Help!
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Hmm. You seem to have overlap, too. I suspect this would be easiest to do in
code - the data you're looking for doesn't exist in the data you have, only
the opposite of that data does.

You could try populating a table with a full day, using the resolution you
need (1 minute resolution means 1440 records) and then (somehow) join with
your data table and use "not between"; but they you'd get a list of free
$resolution blocks, which you may still want to aggregate into from-to
blocks using code.



On Tue, Apr 27, 2010 at 3:47 PM, John Daisley <mg_sv_r@stripped> wrote:

> Hi All,
>
> I have a query I need to run but can't think how to get this working so I
> am
> hoping someone can advise.
>
> I have a table which logs start and end times of Scheduled jobs. It
> includes
> for simplicity a `DayID`, `StartDateTime` and `EndDateTime` column. Both
> `StartDateTime` and `EndDateTime` are 'datetime' datatypes.
>
> What I need to do is find all times in a day when there was nothing running
> on the system - so all times which do not occur between any of the
> `StartDateTime` and `EndDateTime` values for a particular day.
>
> A simple example, if the table had values
>
> *DayId     StartDateTime                EndDateTime
> 1            2010-02-26 16:40:27       2010-02-26 16:41:27
> 1            2010-02-26 16:41:21       2010-02-26 16:45:57
> 1            2010-02-26 16:47:01       2010-02-26 16:49:21
> 1            2010-02-26 16:49:27       2010-02-26 16:49:55
>
> *I can see the system was free between 16:45:57 and 16:47:01 on 26th
> February 2010 and this is what I would need the query to return only
> working
> with a lot more data. Any ideas?
>
> Thank you in advance for any help, suggestions. This is currently on a
> MySQL
> 5.1 system.
>
> Regards
>
>
>
> --
> John Daisley
>
> Certified MySQL 5 Database Administrator
> Certified MySQL 5 Developer
> Cognos BI Developer
>
> Telephone: +44 (0)7918 621621
> Email: john.daisley@stripped
>



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Thread
Query Help!John Daisley27 Apr
  • Re: Query Help!Johan De Meersman27 Apr
  • Re: Query Help!joao27 Apr