http://mixed.dans.knaw.nl/files/TI838D.txt
2009/12/1 Gerald Creager <[email protected]> > My experience in the past (including some .dbf imports by several systems, > including legaccy dBase IV, was that in fact, these are dB-IV .dbf's. The > difference is small, as noted below, between v. III and v. IV. > > gerry > > Peter Hopfgartner wrote: > >> Chris Hermansen wrote: >> >>> Peter; >>> >>> The canonical description of DBase files seems to be >>> >>> http://www.clicketyclick.dk/databases/xbase/format/ >>> >>> >>> >> Well, first of all, I do not know which dBase version is targeted by >> ArcGIS. >> >> Second, I doubt the exact values in >> http://www.clicketyclick.dk/databases/xbase/format/data_types.html#DATA_TYPES. >> >> >> From our tests, both dbase III and dBase IV can handle text fields <= 254 >> characters (and not < 254). >> Further, dBase III can handle numerics with <= 19 digits and not < 18 >> digits. dBase IV limits this to <= 20 digits. >> >> The above mentioned tool identifies ArcGIS generated files as dBase IV, in >> clear conflict on what is said in the above mentioned Wikipedia article. >> >> Cheers, >> >> Peter >> >>> On Tue, 2009-12-01 at 17:28 +0100, Peter Hopfgartner wrote: >>> >>> >>>> Mark Cave-Ayland wrote: >>>> >>>> >>>>> Peter Hopfgartner wrote: >>>>> >>>>> >>>>> >>>>>> Dear PostGIS devels, >>>>>> >>>>>> since we right in the middle of comparing interoperability of shape >>>>>> files between some FOSS programs and ArcGIS, we encoutered also the >>>>>> following: >>>>>> >>>>>> gvSIG chokes on the Bigint as produced by pgsql2shp. Looking at ArcGIs >>>>>> generated files, the max length for numbers is 19, compared to 20 for >>>>>> integers and 32 for floating points as in pgsql2shp. This seems to be >>>>>> confirmed by some Borland tools, when configured for dBase III+. >>>>>> >>>>>> Another limit seems to be that of text fields, that must be no longer >>>>>> then 254. This is the maximum as given by ArcGIS and by the Borland tool. >>>>>> >>>>>> Another point is Boolean: ArcGIS seems to not allow the creation of >>>>>> boolean fields and the Borland Tool ("Database Desktop") says that >>>>>> Booleans >>>>>> have a length of 1. >>>>>> >>>>>> Regards, >>>>>> >>>>>> Peter >>>>>> >>>>>> >>>>> Hi Peter, >>>>> >>>>> You've brought up some interesting points here. Can you actually >>>>> clarify these changes with regard to parts of the official shapefile spec, >>>>> or have they been found purely through experimentation? >>>>> >>>>> >>>>> ATB, >>>>> >>>>> Mark. >>>>> >>>>> >>>>> >>>> Hi Mark, >>>> >>>> I do still have to figure out, if there are public specs for this. All >>>> I've found is, that attributes should be in data base files which are in >>>> dBase format ( >>>> http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf). From the >>>> analysis of the file (and Wikipedia: >>>> http://en.wikipedia.org/wiki/Shapefile), it seems that this should be >>>> dBase III. I do not have any evidence that there is a public spec for dBase >>>> III. >>>> So all we did is basically gather some experimental data, where ArcGIS >>>> and gvSIG are our references. The first, because ESRI introduced the shape >>>> file format and gvSIG, because it is the desktop environment that we >>>> encourage our customers to use. Anyway, we have an old Borland/Inprise tool >>>> ("Database Desktop") here for managing dBase files and used it for our >>>> tests. >>>> >>>> Peter >>>> >>>> >>>> >>> >>> >>> >>> >> >> >> >> ------------------------------------------------------------------------ >> >> >> ------------------------------------------------------------------------ >> >> >> ------------------------------------------------------------------------ >> >> >> _______________________________________________ >> postgis-users mailing list >> [email protected] >> http://postgis.refractions.net/mailman/listinfo/postgis-users >> > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users >
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