PostGIS Queries using FILTER

[Kyle Wilcox]

I just added that layer name into the mail code to avoid confusion, they
are named by their timestamp's index  For example:

First layer:
LAYER
	NAME 'One'
	FILTER "time=TIMESTAMP'2007-11-06 00:00:00'"
	METADATA 'DESCRIPTION' '2007-11-06 00:00:00' END
	...
END

Second Layer:
LAYER
	NAME 'Two'
	FILTER "time=TIMESTAMP'2007-11-06 03:00:00'"
	METADATA 'DESCRIPTION' '2007-11-06 00:00:00' END
	...
END

Those are the only differences between layers.


Could it be that the queryByPoint() function is querying on the specific
point and applying the filter, which fails or returns all timesteps
associated with that point, because the 'time' column is in a separate
table than the geometry column?  I assumed the queryByPoint() function
would join my grid and data tables as specified in DATA.  The grid
geometry (POINTS) are in a separate table than the data (values I want
returned from a query).

The query code is coming from the pmapper framework.  I'll set up a
small test case using Mapserver 4.10 and a self made application to see
if the same thing happens.

Thanks for the response!



Steve Lime wrote:
> Attribute queries use filters themselves so any predefined filter is set aside temporarily. That said, for other
> types of purely spatial queries the FILTER should remain intact. I just stepped through the point query code
> and couldn't any place where it was mucked with.
> 
> What does the code that does that's doing the query look like? I notice in your sample layer that the layer 
> name is 'NAME' which makes me wonder if somehow you're always querying the same layer. Not to say that
> there isn't something else going on as you suggest but I'll start with the obvious.
> 
> Steve
> 
>>>> On 11/6/2007 at 4:00 PM, in message <4730E3F5.2080000 at Noaa.gov>, Kyle Wilcox
> <Kyle.Wilcox at NOAA.GOV> wrote:
>> Did the usual searching without finding anything relevant.
>>
>> The application I am referencing is at:
>> http://155.206.18.162/mapping/map/map.phtml 
>>
>> I have time series data in a PostGIS enabled database (current and wind
>> fields from model output).  I can display the point data without
>> problems (try any of the current or wind layers).
>>
>> The problem is that when querying a point layer, the data that is always
>> extracted from the first timestamp rather than the timestamp associated
>> with the layer I am trying to query (specified as a FILTER).  I understand
>> what is happening.. the query by point functionality is querying the
>> database at the specific POINT and displaying the first row that returns
>> (the first timestamp).  If I delete the first timestamp data, the second
>> timestep data is displayed and so on.  The only thing that changes
>> between layers is the FILTER.
>>
>> Does the queryByPoint() function utilize the FILTER definition from the
>> mapfile?  It doesn't seem to be doing so.
>>
>> (Mapserver 5.0 and PHP/Mapscript)
>>
>>
>>  Here is a sample layer definition:
>>
>>      LAYER
>>                  TYPE POINT
>>                  CONNECTIONTYPE postgis
>>                  NAME 'NAME'
>>                  CONNECTION 'host=HOST user=USER dbname=DATABASE'
>>                  DATA "the_geom from (SELECT * from forecast left join
>>  grid on grid.gid=forecast.grid_id) as data USING UNIQUE gid USING
>>  SRID=4326"
>>                  FILTER "time=TIMESTAMP'2007-11-06 00:00:00'"
>>                  METADATA
>>                          'DESCRIPTION' '2007-11-06 00:00:00'
>>                          'RESULT_FIELDS'
>>  'wind_speed,wind_from_direction,rotation'
>>                          'RESULT_HEADERS' 'Wind Speed (m/s), Wind
>>  Direction (from TN), Rotation of Image (from TN)'
>>                          'LAYER_ENCODING' 'UTF-8'
>>                  END
>>                  STATUS OFF
>>                  PROJECTION
>>                          'init=epsg:4326'
>>                  END
>>                  TOLERANCE 10
>>                  TOLERANCEUNITS pixels
>>                  LABELMAXSCALE 60000
>>                  TEMPLATE void
>>          CLASS
>>                      NAME ">= 0.95 m/s"
>>                      EXPRESSION ([wind_speed] >= 0.95)
>>                      STYLE
>>                              SYMBOL "arrow2"
>>                                ANGLE [wind_from_direction]
>>                              COLOR 118 0 0
>>                              OUTLINECOLOR 0 0 0
>>                              SIZE 10
>>                      END
>>                      TEXT ([wind_speed] m/s - [wind_from_direction] TN)
>>                      LABEL
>>                              COLOR 118 0 0
>>                              OUTLINECOLOR 0 0 0
>>                              POSITION AUTO
>>                              SIZE small
>>                              PARTIALS TRUE
>>                      END
>>              END
>>          ...
>>      END
>>
>> -- 
>>
>>  Kyle Wilcox
>>  NOAA Chesapeake Bay Office
>>  410 Severn Avenue
>>  Suite 107A
>>  Annapolis, MD 21403
>>  office: (410) 295-3151
>>  Kyle.Wilcox at noaa.gov 
>>
>>  "It is from the wellspring of our despair and the places
>>   that we are broken that we come to repair the world."
>> 						- Murray Waas
> 

-- 

 Kyle Wilcox
 NOAA Chesapeake Bay Office
 410 Severn Avenue
 Suite 107A
 Annapolis, MD 21403
 office: (410) 295-3151
 Kyle.Wilcox at noaa.gov

 "It is from the wellspring of our despair and the places
  that we are broken that we come to repair the world."
						- Murray Waas