Cannot populate all fields using spatial join script tool

Question

I am trying to create a script tool that spatially joins point and polygon features so that they create a new feature class with only user specified fields included. I have created a parameter that allows the user to check off which fields they want to include, but if both input and target feature classes have the same field name in their table, only one of the fields will be populated in the output table (ie. both have NAME field). If I use the spatial join tool the new table will include populated NAME and NAME_1 fields, but not in a script. I have also tried to check the 'maintain fully qualified fieldnames' in environments so that each field name is unique, but this doesn't seem to help. If anyone has any idea it would be greatly appreciated. Thanks

Jesse

JoelCalhoun · Answer

If you can't alter the fields in the input datasets can you simply make a temporary copy or a feature layer and alter that?

Also I remember having some issues with Field Mappings a few years ago so I ended up just exporting the combined field map to a string and doing some manipulations on that string.

I have included my script tool in case the full script is of some use though it is intended for a table join to a feature class.

Joel

TableJoin_to_FeatureClass.zip

Anonymous User · Answer

I would suggest looking at how the "Field Mapping" data type parameter stores the list of the fields that are selected by the user. You can do this by using the arcpy.AddMessage("Field list: "+ field_list) to print the list of selected fields to results window. If the field mappings stores these values in a similar manner to the multi-value input (a string list separated by semicolons), you can simply do the split by ";" as I mentioned before. Once you see how the list is stored, it will make it a lot easier for you to figure out how to test for duplicate field values between to two feature classes.

However, now that I think about it, I am not sure that what I suggested will allow you to change the name of the duplicate field (I have not played around with the field mapping data type too much). If this is the case, you could use the if statement that I provided to look for duplicate fields. If a duplicate exists, you can add a field with the same name + "_1" and use an update cursor to get the values from the original field.

I was able to accomplish renaming the field name objects using the original code I provided while testing:
input1 = r'G:\Data\Geodatabase\Cedar_County.mdb\ADDRESS\Addresses'
input2 = r'G:\Data\Geodatabase\Cedar_County.mdb\CADASTRAL\PARCEL'

try:
    
    lista = [f.name for f in arcpy.ListFields(input1)] 
    listb = [fb.name for fb in arcpy.ListFields(input2)] #
    print lista
    print listb
    for fielda in lista:  
        for fieldb in listb:
            if fielda == fieldb:
                fieldb = fieldb + '_1'
                print fieldb
            else:
                pass

It returned this:
[u'OBJECTID', u'Shape', u'PID', u'HOUSENUM', u'ADDRESS', u'CITY', u'GID', u'UNIT', u'Verify_add', u'Add', u'Type', u'Need_GPS', u'Business', u'Prefix', u'Street', u'Suffix', u'FULL_ADD', u'Full_Str', u'POINT_X', u'POINT_Y', u'BLUE_TAG', u'NOTES', u'ESN', u'ZIP', u'SOL_PID']
[u'OBJECTID', u'PID', u'GIS_ACRES', u'SOL_PID', u'SHAPE', u'SHAPE_Length', u'SHAPE_Area']
OBJECTID_1
PID_1
SOL_PID_1

All duplicate fields had the "_1" added in listb. Where I have the print fieldb line is where I would add code to add these fields and use an update cursor to grab the original values.

JesseMorkis · Answer

Thanks Joel and Caleb. This last script is exactly what I am looking for, except for the fact that I can't alter any of the fields within the layers that I am working with. I think what Caleb suggested is more along the right path for what I am going to have to do because it actually alters the list of field parameters rather than the fields in the feature class. My only problem now is when i call the spatial join tool in the script I have to include a field mapping for what I will be including in my output feature class. It could get a bit tricky doing this, but I think it is possible.