I'm trying to add attributes (in excel format) to an existing shapefile using ArcGIS, but the number of records between the two are not the same; there are some records in one file but not in the other, and vice versa. I'm new to GIS field and not sure what steps to take, but here's what I think will work:
- Export attributes from shapefiles to database format, convert it to excel format
- Merge shapefile attribute with the other excel attribute to form one file
- Retain those from shapefile attribute
- Import new data back to the shapefile
Do you think this will work? Especially at step 4, can I import new data (i.e., with updated attributes) in the excel form to the shapefile in some way? Sorry if it's looks too rudimentary/crude a plan, but to my beginner level that makes some sense intuitively.
The reason I think I have to use Excel is because the ID field (FID) is available in the shapefile but not in the Excel. What they have in common is the description of the FID; in this data, the descriptive fields include county, district, and province. In addition, these descriptive fields are collectively unique but not individually unique; that is, it may be that some counties have the same name, but they belong to different districts (or even the same district but different provinces). So what I can think of is to export data and work on Excel, or whatever external program (a statistical one will do), to assign FID to the additional attribute table, before joining/relating them. But does ArcGIS allow joining/matching using more than one ID fields?
The relationship is one (of the shapefile) to many (of the additional attribute table). How does it complicate the joining/relating plan?