Hi, > What might happen when user is saving into shapefile a dataset with > attributes like "long_attribute_name_01" and "long_attribute_name_02"? > Truncating names to suit the .dbf format would yield to identical names. This > is how GDAL behaves: > > Attribute names can only be up to 10 characters long. Longer names will be > silently truncated. This may result in non-unique column names, which will > definitely cause problems later. > > Starting with version 1.7, the OGR Shapefile driver tries to generate unique > field names. Successive duplicate field names, including those created by > truncation to 10 characters, will be truncated to 8 characters and appended > with a serial number from 1 to 99. Yes, this is a good idea. This is also the way short file names are written by windows to follow the old 8.3 convention. Should not be too hard to implement.
Michaël > > For example: > > a → a, a → a_1, A → A_2; > abcdefghijk → abcdefghij, abcdefghijkl → abcdefgh_1 > > Taken from http://gdal.org/ogr/drv_shapefile.html > > -Jukka Rahkonen- > > > ________________________________________ > Lähettäjä: SourceForge.net [nore...@sourceforge.net] > Lähetetty: 10. tammikuuta 2012 23:28 > Vastaanottaja: SourceForge.net > Aihe: [JPP-Devel] [ jump-pilot-Bugs-3472008 ] AssertionFailedException with > two identical attribute name > > Bugs item #3472008, was opened at 2012-01-10 13:28 > Message generated for change (Tracker Item Submitted) made by michaudm > You can respond by visiting: > https://sourceforge.net/tracker/?func=detail&atid=679906&aid=3472008&group_id=118054 > > Please note that this message will contain a full copy of the comment thread, > including the initial issue submission, for this request, > not just the latest update. > Category: OpenJUMP - Menu - Edit > Group: None > Status: Open > Resolution: None > Priority: 5 > Private: No > Submitted By: michael michaud (michaudm) > Assigned to: Nobody/Anonymous (nobody) > Summary: AssertionFailedException with two identical attribute name > > Initial Comment: > How can two identical attribute names happen ? > - with a sql query : ex. select geom, name, name, name from city > (although I don't think a plain table can have duplicate names) > - it can be saved/read to/from a shapefile, a jml (with different results !) > - feature schema edition tool pevent such a schema edition > > What happens ? > - a AssertionFailedException is thrown by plugins like > * combine selected layers > * clip map to fence > * there are other problems if one try to change an attribute value using > its name... > > What to do ? > The minimum would be to throw a clearer message > Maybe sufficient, automatic renaming seems a bit dangerous > Refusing data loading maybe frustrating (although getting a yellow warning > light be useful) > > Michaël > > > ---------------------------------------------------------------------- > > You can respond by visiting: > https://sourceforge.net/tracker/?func=detail&atid=679906&aid=3472008&group_id=118054 > > ------------------------------------------------------------------------------ > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ------------------------------------------------------------------------------ > Write once. Port to many. > Get the SDK and tools to simplify cross-platform app development. Create > new or port existing apps to sell to consumers worldwide. Explore the > Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join > http://p.sf.net/sfu/intel-appdev > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel ------------------------------------------------------------------------------ Write once. Port to many. Get the SDK and tools to simplify cross-platform app development. Create new or port existing apps to sell to consumers worldwide. Explore the Intel AppUpSM program developer opportunity. appdeveloper.intel.com/join http://p.sf.net/sfu/intel-appdev _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
