Assign Default To Field (Data Management)

Summary

Creates a default value for a specified field. When a new row is added to the table or feature class, the specified field will be set to this default value.

Usage

Caution:

This tool modifies the input data. See Tools that modify or update the input data for more information and strategies to avoid undesired data changes.

• The default value is dependent on the field type chosen in the Field Name parameter. If you choose a field that is type LONG (long integer), the default value must be type LONG.

• Adding subtypes to the default value is optional. If you add a subtype, there must be a subtype field in the feature class or table. You can set the subtype field using the Set Subtype Field tool.

• You can also view and manage subtypes in Subtypes view which can be opened by clicking the Subtypes button found in the Design section of the Data ribbon, or by clicking the Subtypes button on the Fields view ribbon.

• This tool can also be used to clear the default value of a field or subtype.

Parameters

Dialog

Label	Explanation	Data Type
Field Name	The field to which the default value will be added each time a new row is added to the table or feature class.	Field
Subtype (Optional)	The subtypes that can participate in the default value.	String
Clear Value (Optional)	Specifies whether the default value for either the field or the subtype will be cleared. The Default Value parameter must be empty to clear the default value of the field. To clear the default value for the subtype, leave the Default Value parameter empty and specify the subtype to be cleared. Checked—The default value will be cleared (set to null). The default value parameter must be empty. Unchecked—The default value will not be cleared. This is the default.	Boolean

Derived Output

Label	Explanation	Data Type
Updated Input Table	The updated input table.	Table View; Raster Layer; Mosaic Layer

Python

arcpy.management.AssignDefaultToField(field_name, {subtype_code}, {clear_value})

Name	Explanation	Data Type
field_name	The field to which the default value will be added each time a new row is added to the table or feature class.	Field
subtype_code [subtype_code,...] (Optional)	The subtypes that can participate in the default value.	String
clear_value (Optional)	Specifies whether the default value for either the field or the subtype will be cleared. To clear the default value, the default_value parameter must be passed in as an empty string. To clear the default value for the subtype, you must also specify the subtype to be cleared.	Boolean

Derived Output

Name	Explanation	Data Type
out_table	The updated input table.	Table View; Raster Layer; Mosaic Layer

Code sample

AssignDefaultToField example (Python window)

The following Python window script demonstrates how to use the AssignDefaultToField function in immediate mode.

import arcpy
arcpy.env.workspace = "C:/data/Montgomery.gdb/Landbase"
arcpy.CopyFeatures_management("blocks", "C:/output/output.gdb/blocks")
arcpy.AssignDefaultToField_management("C:/output/output.gdb/blocks", "Res", 1,
                                      ["0: Non-Residental", "1: Residental"])

AssignDefaultToField example 2 (stand-alone script)

The following stand-alone script demonstrates how to use the AssignDefaultToField function.

# Name: AssignDefaultToField_Example2.py
# Description: Assign a new default to a field along with subtypes
 
# Import system modules
import arcpy
 
# Set environment settings
arcpy.env.workspace = "c:/data/Montgomery.gdb/Landbase"
 
# Set local variables
inFeatures = "blocks"
outFeatureClass = "c:/output/output.gdb/blocks"
fieldName = "Res"
defaultValue = 1
subTypes = ["0: Non-Residental", "1: Residental"]
 
# Execute CopyFeatures to make new copy of the input
arcpy.CopyFeatures_management(inFeatures, outFeatureClass)
 
# Execute AssignDefaultToField
arcpy.AssignDefaultToField_management(outFeatureClass, fieldName, 
                                      defaultValue, subTypes)

Environments

Current Workspace