[GRASS-dev] [GRASS GIS] #3068: Raise a warning/error when where parameter is not correctly set

GRASS GIS trac at osgeo.org
Thu Jun 23 06:01:29 PDT 2016

#3068: Raise a warning/error when where parameter is not correctly set
  Reporter:  veroandreo   |      Owner:  grass-dev@…
      Type:  enhancement  |     Status:  new
  Priority:  normal       |  Milestone:  7.3.0
 Component:  Temporal     |    Version:  svn-trunk
Resolution:               |   Keywords:  where
       CPU:  Unspecified  |   Platform:  Linux

Comment (by veroandreo):

 Replying to [comment:1 mlennert]:
 > Replying to [ticket:3068 veroandreo]:
 > > I have a set of 16 years of MODIS data starting on February 18, 2000.
 My intention was to aggregate data seasonally (3 months granularity), but
 as start is shifted, I wanted aggregation to start from April 1st. This
 was my command:
 > >
 > > {{{
 > > t.rast.aggregate --o input=${var}_${tile} method=average \
 > > output=${var}_${tile}_seasonal_average \
 > > basename=${var}_${tile}_seasonal_average \
 > > suffix=gran where="start_time >= 2000-04-01 00:00:00" \
 > > granularity="3 months"
 > > }}}
 > >
 > > I forgot to write 'single quotes' around the date. Therefore, the
 where parameter was ignored and all my seasons shifted and I had to
 > > run all over again.
 > >
 > > Would that be possible to check if the where clause is "well-written"
 and raise an error/warning if it is not??
 > The problem will be to define "well-written". AFAIK, the "check" is
 currently done by the db backend: if it accepts the formulation, then ok,
 if not, you'll see an error.

 I see... but according to the definition in the manual, this where is in
 the temporal framework, so I imagined it could be something like if
 there's start_date or end_date in the left hand side, then check for
 single quotes around the right hand part of the expression... maybe too

 > So apparently your backend considers your where clause as being correct
 in terms of syntax.

 So, it is an SQLite issue, that is not sensitive to that kind of mistakes?

 > And we won't be able to create and intelligent system that will be able
 to tell whether what you write is actually what you mean... ;-)

 meep! :)

Ticket URL: <https://trac.osgeo.org/grass/ticket/3068#comment:2>
GRASS GIS <https://grass.osgeo.org>

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