Shapefiles are not retaining Feature ID info
December 19, 2013 Leave a comment
An iCMTGIS II user wrote that the Shapefiles exported from the iCMTGIS II app does not contain the Feature Ids so that he was unable to bring in the Feature ID labels using his external PC software.
The Shapefiles format does not provide for Feature IDs per se. The zero-based FID in Shapefiles are record IDs rather than Feature IDs. In other words, if you delete one of the Feature records, its FID will change.
The Feature IDs are assigned by our apps when you import Shapefiles into iCMTGIS II, iGPSGIS II, Utility Data Collection, Farming GPS GIS or Forester GPS GIS. You may label the Features with their Feature IDs. If you open Shapefiles in the PC-GIS software, the Feature IDs will be automatically assigned by the PC-GIS software. Like PC-GIS 09, the Utility Data Collection provides the Feature_ID as a built-in Attribute that you can add to any Topic.
If you are using some other PC software that accepts Shapefiles and is able to label the Features with their Attributes, you could add an Attribute field, such as ID_No, to your Topic layer in iCMTGIS II and enter the ID numbers via Sheet View. Then export to Shapefiles.
You could also add the ID_No Attribute to your Feature List so you may enter the ID while collecting the GPS data.
Another thing to note is that Shapefiles use the .DBF format to store Attributes/Values and the field width limit is 10 characters.