error message

[John Bolster]

Thanks Steve,

I have various layers of tiger/line data organized into one directory per
county and I've been trying to make one tileindex for the whole thing. Based
on what you're saying, do I need to run tile4ms separately on each different
type of layer, so that I end up with a tileindex for the counties, one for
the roads, one for the places, etc.?

John

> -----Original Message-----
> From: Stephen Woodbridge [mailto:woodbri at swoodbridge.com]
> Sent: Tuesday, September 21, 2004 10:22 AM
> To: John Bolster
> Cc: MAPSERVER-USERS at LISTS.UMN.EDU
> Subject: Re: [UMN_MAPSERVER-USERS] error message
>
>
> John,
>
> The way tileindexes work is the you group a bunch of files into a
> virtual layer. All the files must have the same dbf columns defined in
> them and defined in the same order. This is because mapserver reads the
> attribute layout of the first file it opens and uses that as the
> template for all files in the virtual layer.
>
> So if the first file had attribute columns [A, B, C] and some other file
> had [D, E] or [B, C, A] or whatever it would cause problems for
> mapserver. If you ask mapserver to CLASS on C, it translates that to
> column 3 and then tries to read column 3 from the [D, E] and gets an
> error, or gets column A from [B, C, A] file, etc. This was causing a lot
> of problems for people that did not understand the inner workings of
> mapserver, so this check was added to prevent people from doing bad
> things and not knowing about it.
>
> Some version of dbfdump will display the column definitions of you
> files. You either have some that have a different definition like a
> different version of the file, or you are picking up some files that are
> not compatible with the first file you add to the index.
>
> Hope this helps,
>    -Steve W.
>
> John Bolster wrote:
>
> > Hello,
> >
> > Does anyone know what "DBF fields do not match" means in the output from
> > tile4ms?
> >
> > Do they not match to one another, or to a certain way they're
> meant to be,
> > or to the shapefile, or what? The files were created with
> tgr2shp so I don't
> > see why they should be bad. And what would I do about this--I
> can't imagine
> > I'm the only person to whom this has happened.
> >
> > Thanks for your help,
> > John Bolster
> >
>
>