ArcMap

Assign Default To Field

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

  • 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.

  • The subtypes of a feature class or table can also be managed in the Catalog window. Subtypes can be created and modified using the Subtypes Property page on the dataset Properties dialog box.

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

Syntax

arcpy.management.AssignDefaultToField(in_table, field_name, {default_value}, {subtype_code}, {clear_value})
ParameterExplanationData Type
in_table

The input table or feature class that will have a default value added to one of its fields.

Mosaic Layer; Raster Catalog Layer; Raster Layer; Table View
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
default_value
(Optional)

The default value to be added to each new table or feature class. The value entered must match the data type of the field.

String
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.

  • TRUE —The default value will be cleared (set to null).
  • FALSE —The default value will not be cleared. This is the default.
Boolean

Derived Output

NameExplanationData 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

Licensing information

  • Basic: Yes
  • Standard: Yes
  • Advanced: Yes

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