[mapserver-dev] numeric values in string columns

[Kralidis,Tom [Ontario]]

> -----Original Message-----
> From: mapserver-dev-bounces at lists.osgeo.org 
> [mailto:mapserver-dev-bounces at lists.osgeo.org] On Behalf Of 
> Yewondwossen Assefa
> Sent: Monday, November 10, 2008 9:14 AM
> To: Bart van den Eijnden (OSGIS)
> Cc: mapserver-dev at lists.osgeo.org; Daniel Morissette
> Subject: Re: [mapserver-dev] numeric values in string columns
> 
> 
> Daniel Morissette wrote:
> > bartvde at osgis.nl wrote:
> >> Hi list,
> >>
> >> we've got a dataset with road numbers, the column in ArcSDE is a 
> >> character type. But the values can look like numbers (002 etc.) as 
> >> well as strings (e.g. N329).
> >>
> >> Mapserver will fail in this case, seeing it will check the 
> value for 
> >> determining the type of column (mapogcfilter.c).
> >>
> >> Will this be easy to fix, or will it require that Mapserver stores 
> >> column types internally?
> >>
> > 
> > I'll let Assefa answer about mapogcfilter.c specifically, 
> but I think 
> > it would be a good thing to maintain the original column type.
> > 
> > I started working on support for column types in MapServer 
> a few years 
> > ago but never finished it... I think that may even have 
> been for WFS...
> > I checked this morning and unfortunately I could not find that code 
> > anywhere.
> > 
> > Daniel
> 
> 
> 
> Ideally if the layer's column type is available with the 
> layer object, we could use that. Not sure when/if that will 
> be available.
> The other alternative is to use metadata on the layer (the 
> same way we use it now for attribute name aliases). We could 
> have <item_name>_type and have that value used  to build the 
> expressions. I am willing to add the metatadata support if 
> you think this is appropriate.
> 

This would also be useful for WFS DescribeFeatureType output, as the
schema response can map to the actual datatypes (and output, say,
xs:integer, xs:datetime, etc.) if specified.

..Tom