[mapserver-users] some questions regarding getFeatureInfo, SLD, PostGIS

Fri Sep 21 05:22:46 PDT 2012

What I've done is have the join in the sql but either join it to the
correct join column or join it to a null match (and make it an outer
join). 

I typically use oracle syntax and not ansi syntax but the trick is to have
all the table joins in the sql but using case to alter the join condition.

On 9/21/12 8:06 AM, "Julien Cigar" <jcigar at ulb.ac.be> wrote:

>On 09/21/2012 13:24, Smith, Michael ERDC-RDE-CRREL-NH wrote:
>> At the SQL level, you can do some fancy work with CASE and setting some
>> default values
>>
>> The CASE function allows you to set all kind of logical comparisons. You
>> can do conditional joins that way, setting the join condition to a non
>> matching value when you don't want the join, etc. SQL is more powerful
>> than any template language.
>
>You'll have to explain me how you add a JOIN clause through a CASE
>statement ..? :)
>
>> Mike
>>
>>
>>
>> On 9/21/12 7:07 AM, "Julien Cigar"<jcigar at ulb.ac.be>  wrote:
>>
>>> On 09/21/2012 12:50, Rahkonen Jukka wrote:
>>>> Hi,
>>> Hello,
>>>
>>>> So you have tried to define variables %SEX% and %BOD_ID%, used them
>>>> inside your DATA and then fired  WMS GetMaps by
>>>> adding&SEX=your_value&BOD_ID=your_id? Does in not work or why it is
>>>>not
>>>> powerful enough?
>>> It is not powerful enough because it doesn't allow you to make simple
>>> logical tests (if defined/equals/...), the run-time substitution is a
>>> simple "replace %FOO%" by the value of FOO= from the query string.
>>>
>>> It doesn't allow you to do something like: "if FOO is defined or equal
>>> to xxx, then add "JOIN foo f ON f.id = bar.foo_id", select additional
>>> columns, and add a "WHERE foo.id = ..." at a certain place in the DATA
>>> string".
>>>
>>> I guess mapscript should be used in this case, but it would be really
>>> interesting to have this simple template language (or another solution)
>>> without having to involve mapscript.
>>>
>>> Julien
>>>
>>>> -Jukka Rahkonen-
>>>>
>>>>
>>>> Julien Cigar wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I'm using Mapserver 6.0.1 with the following PostGIS layer:
>>>>> http://pastie.org/private/84042k84vmljbontls5xvq
>>>>>
>>>>> The user has the possibility to select quite a lot of filters, which
>>>>> implies that
>>>>> the SQL query should, in theory ,be generated dynamically.
>>>>> As this is not possible with Mapserver (run-time substitution with
>>>>>HTTP
>>>>> parameters and VALIDATION ... END isn't powerful enough is my case),
>>>>> I'm
>>>>> dynamically generating an SLD
>>>>> (http://pastie.org/private/p66ml3uvqwcnphuuvera) to filter items and
>>>>>it
>>>>> works very well.
>>>>>
>>>>> Some questions:
>>>>>
>>>>> - Why does Mapserver doesn't have a very lightweight template
>>>>>language
>>>>> (or
>>>>> something similar) to dynamically build a string following given
>>>>> parameters? It
>>>>> could be really useful to avoid unnecessary JOIN, etc.
>>>>> For example something like:
>>>>> http://pastie.org/private/bojm3pi1dwrv18m2tvq (this is just an
>>>>> example, but
>>>>> the idea is there)
>>>>>
>>>>> - I noticed in the PostgreSQL logs that sometimes Mapserver adds an
>>>>> additional condition to the WHERE clause when SLD is used. For
>>>>>example
>>>>> with
>>>>> the following<ogc:Filter>   in my SLD:
>>>>> #########################################
>>>>> <ogc:Filter>
>>>>> <ogc:PropertyIsEqualTo>
>>>>> <ogc:PropertyName>basis_of_record_id</ogc:PropertyName>
>>>>> <ogc:Literal>1</ogc:Literal>
>>>>> </ogc:PropertyIsEqualTo>
>>>>> </ogc:Filter>
>>>>> #########################################
>>>>>
>>>>> Mapserver adds an additional "and (( ("basis_of_record_id"= 1) ))":
>>>>>
>>>>> (...) AS q where geom&&   GeomFromText('POLYGON((-3.6860351557368
>>>>> -9.81732918571448,-3.6860351557368 9.81732918571447,47.6860351496117
>>>>> 9.81732918571447,47.6860351496117 -9.81732918571448,-3.6860351557368
>>>>> -9.81732918571448))',4326) and (( ("basis_of_record_id"= 1) ))
>>>>>
>>>>> which is not bad as less rows have to be post-processed by the SLD
>>>>> engine.
>>>>>
>>>>> However, as soon as I add an additional<ogc:or>   (or<ogc:and>) as:
>>>>> #########################################
>>>>> <ogc:or>
>>>>> <ogc:PropertyIsEqualTo>
>>>>> <ogc:PropertyName>basis_of_record_id</ogc:PropertyName>
>>>>> <ogc:Literal>1</ogc:Literal>
>>>>> </ogc:PropertyIsEqualTo>
>>>>> <ogc:PropertyIsEqualTo>
>>>>> <ogc:PropertyName>basis_of_record_id</ogc:PropertyName>
>>>>> <ogc:Literal>2</ogc:Literal>
>>>>> </ogc:PropertyIsEqualTo>
>>>>> </ogc:or>
>>>>> #########################################
>>>>>
>>>>> Mapserver doesn't add this additional AND/OR clause (and ((
>>>>> ("basis_of_record_id"= 1) OR ("basis_of_record_id" = 2) )) in this
>>>>> case).. Why
>>>>> ?
>>>>>
>>>>> - Is it normal that my SLD is totally ignored when I'm using
>>>>> REQUEST=GetFeatureInfo? Is the SLD only processed with
>>>>> REQUEST=GetMap?
>>>>> If this is the case, what's the typical alternative way of doing it?
>>>>> Should I go through WFS .. ?
>>>>>
>>>>> In advance, thank you for your answers :) Julien
>>>>>
>>>>> --
>>>>> No trees were killed in the creation of this message.
>>>>> However, many electrons were terribly inconvenienced.
>>>> _______________________________________________
>>>> mapserver-users mailing list
>>>> mapserver-users at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>
>>> -- 
>>> No trees were killed in the creation of this message.
>>> However, many electrons were terribly inconvenienced.
>>>
>
>
>-- 
>No trees were killed in the creation of this message.
>However, many electrons were terribly inconvenienced.
>