В сообщении от Wednesday 18 June 2008 21:32:46 Dennis Cote написал(а):
> Alexey Pechnikov wrote:
> > There is problem for select one row by time - we must use query
> > select * from events where time || =julianday('2008-06-16 23:59:59.999');
> > and index is not used for this query.
> > Maybe patch http://www.sqlite.org/cvstrac/chngview?cn=5215
> > resolved problem but I'm not sure.
>
> There is no problem with this except that it is usually unreliable to do
> equality comparisons with floating point data such as julian day numbers.
>
> When you say "select one row by time" do you mean that there can only be
> one row in each millisecond period, or do you really mean that you want
> all the rows within that one millisecond period, or perhaps you only
> want the first row in that millisecond period.
>
> In any case, the secret is to know what your required time resolution
> is, and use a normal range query to select rows using the start and end
> times of that period. For a one millisecond long period you can use:
>
> select * from events
> where time between julianday('2008-06-16 23:59:59.999')
> and julianday('2008-06-16 23:59:59.999') + 1.0/(86400000)
>
> or
>
> select * from events
> where time between julianday('2008-06-16 23:59:59.999')
> and julianday('2008-06-17 00:00:00.000')
>
I find get only _one_ row. I found correspond timestamp by other questions. I
don't want get more than one row.
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