Qualified Field Names (Environment setting)
Tools that honor the Qualified Field Names environment will use this setting to distinguish between qualified or unqualified field names. Qualified field names are the names of fields in a feature class or table that have the name of the origin feature class or table appended onto the field name itself. This setting is relevant when working with joined data.
Usage notes
- The default qualified output table field naming structure is tableName.fieldName. When unqualified, the fields in the output table or feature class will always be named with the format fieldName.
- In instances where qualified field names may exceed the allowed field name width, you should set the environment to UNQUALIFIED—for example, when joining shapefiles. Shapefile fields are truncated at eight characters.
When field mappings are included in a tool's parameters, as they are in many tools in the Conversion toolbox, field names are automatically UNQUALIFIED, so there is no need to set this environment.
Dialog syntax
- Checked—The output field name will include the table name. This is the default.
- Unchecked—The output field name will not include the table name.
Scripting syntax
arcpy.env.qualifiedFieldNames = qualified_field_names
qualified_field_names |
Explanation |
---|---|
True |
The output field name will include the table name. This can also be set using the QUALIFIED keyword. This is the default. |
False | The output field name will not include the table name. This can also be set using the UNQUALIFIED keyword. |
# Name: addjoin.py
# Purpose: Join a table to a featureclass and have the output
# unqualified
# Author: ESRI
# Import system modules
import arcpy
from arcpy import env
try:
# Set environment settings
env.workspace = "C:/data"
env.qualifiedFieldNames = False
# Set local variables
inFeatures = "Habitat_Analysis.gdb/vegtype"
layerName = "veg_layer"
joinTable = "vegtable.dbf"
joinField = "HOLLAND95"
expression = "vegtable.HABITAT = 1"
outFeature = "Habitat_Analysis.gdb/vegjoin"
# Create a feature layer from the vegtype featureclass
arcpy.MakeFeatureLayer_management(inFeatures, layerName)
# Join the feature layer to a table
arcpy.AddJoin_management(layerName, joinField, joinTable, joinField)
# Copy the layer to a new permanent feature class
# Output fields are unqualified, so the field name will
# not contain the origin table
arcpy.CopyFeatures_management(layerName, outFeature)
except Exception, e:
# If an error occurred, print line number and error message
import traceback, sys
tb = sys.exc_info()[2]
print "Line %i" % tb.tb_lineno
print e.message