I think we're misunderstanding... I don't have an external dbf file to tie. I'm talking about the *shape dbf* file (shp shx -->dbf<--): this file contains records not linked to the geometry in the related shp file. Infact all the geometries have their own data but there are plenty data without a geometry (these are no spatial data, not linkable to the geometries). Files are not corrupted because they're intentionally made in this way.
No spatial data are useful for me because when you search for them you should have the answer: data + "unlocatable". Gail Long told me he added a search function to parse the shape dbf searching for records without geometry tie, then he migrated to postgis & postgres because search was faster. Any other suggestion? thanks in advance, bye ----- Original Message ----- From: Armin Burger To: Gail Long Cc: fiorenontaglio a libero.it ; pmapper-users a faunalia.it Sent: Wednesday, May 24, 2006 11:18 PM Subject: Re: [Pmapper-users] attribute query and records with no geometry Just a more general remark using dbf files and querying them with PHP: If for whatever reasons whatsoever you need to use them and not putting the data into a real DB, on Windows you can speed up things via ODBC. If you have MS Access, just define an MDB and link the dBase files to it as external data source. Then access the MDB via the ODBC driver. Works *much* faster than native dbf functions. Another remark for shapefiles and dbf: If you modify the dbf part of a shapefile with pure dBase functions/programs, and add or remove records, you might get into trouble sooner or later with a corrupt shapefile that is not readable any more. Armin Gail Long wrote: > Tony, > > A layer is made up of shape files for geometry and data in the dbf files for > attributes. If there is no tie to the geometry there are no records to be > returned. > > However, I had a similar need and know that what you want to do can be done. > I have several .dbf files that have lots of useful data in them. For the > most part I've been able to use a pmapper JOIN and tie the data uniquely to > a record in a shape file ( a feature) by adding a key field to the dbf > tables that links back to my Postgres tables. This should work the same way > with shape files and link back to an attribute. > > With two of the tables however, I don't have a clean way to join them to a > geographic feature. So, in order to get to that data I added an additional > search form to search.phtml, and copied info.phtml and called a dbase search > using php to return records from the table with no shapefile ties. After > using this method for awhile and finding it slow, I've converted the dbf > files to a postgres tables so that its easier to deal with them and I can > index them for MUCH better performance. > > This worked so well for me that I've extended this to do searches on a > couple of mysql dbs as well. > > As to mapping, I'm very close to finding a quick way to create point data in > a shape so that each of my featureless data records will now be able to be > mapped when I want them mapped. > > In order to do this you'll have to either write a new query class and a > couple of new print functions, or alter the ones that Armin has provided, so > that it will create a zoompoint link rather than zoomextent. Not trivial > but not too difficult either. Because I wasn't mapping these tables I just > encapsulated all of that functionality in my altered info_data.phtml. > > I do encourage you to setup Postgres with PostGIS if you are planning on > doing much pure data manipulation. The windows installer for Postgres and > PostGIS are very simple to use and you'll find that you gain lots of > advantages over using shape files and dbf files. > > Good luck! > -- > Things are only difficult while you don't understand them. > > > > >> From: "toni" <fiorenontaglio a libero.it> >> To: "pmapper mailing list" <pmapper-users a faunalia.it> >> Subject: [Pmapper-users] attribute query and records with no geometry >> Date: Tue, 23 May 2006 23:23:05 +0200 >> >> Hi everybody, >> >> i'm using win xp, ms4w v.1.5.0, pmapper 1.2.0, shape files for layers. >> >> I've set as pmapper layer a shape file including records without geometry >> (let me explain: my shape .dbf file contains records not linked with the >> objects in the .shp file, these records do not have geographic >> localization). >> If I use the attribute query in the search frame looking for a record >> without geometry I get: "no data found", when instead data are stored. >> >> Does the attribute query work only if the geometry exists or not? >> I created a "conventional geometry" for these records just to make the >> query >> work, but it doesn't seem the most correct way to avoid the problem (bigger >> file for nothing, slow map loading) >> >> thanks >> toni >> >> >> >> _______________________________________________ >> Pmapper-users mailing list >> Pmapper-users a faunalia.it >> http://faunalia.it/cgi-bin/mailman/listinfo/pmapper-users > > > > _______________________________________________ > Pmapper-users mailing list > Pmapper-users a faunalia.it > http://faunalia.it/cgi-bin/mailman/listinfo/pmapper-users > >
