Create Domain (Data Management)

License Level:BasicStandardAdvanced

Summary

Creates an attribute domain in the specified workspace.

Usage

Syntax

CreateDomain_management (in_workspace, domain_name, domain_description, field_type, {domain_type}, {split_policy}, {merge_policy})
ParameterExplanationData Type
in_workspace

The geodatabase that will contain the new domain.

Workspace
domain_name

The name of the domain that will be created.

String
domain_description

The description of the domain that will be created.

String
field_type

The type of attribute domain to create. Attribute domains are rules that describe the legal values of a field type. Specify a field type that matches the data type of the field to which the attribute domain will be assigned.

  • SHORTNumeric values without fractional values within a specific range; coded values.
  • LONGNumeric values without fractional values within a specific range.
  • FLOATNumeric values with fractional values within a specific range.
  • DOUBLENumeric values with fractional values within a specific range.
  • TEXTNames or other textual qualities.
  • DATEDate and/or time.
String
domain_type
(Optional)

The domain type to create:

  • CODEDSpecifies a valid set of values for an attribute. For example, a coded value domain might specify valid pipe material values: CL—cast iron pipe, DL—ductile iron pipe, or ACP—asbestos concrete pipe.
  • RANGESpecifies a valid range of values for a numeric attribute. For example, if distribution water mains have a pressure between 50 and 75 psi, then a range domain would specify these minimum and maximum values.
String
split_policy
(Optional)

The split policy of the created domain. The behavior of an attribute's values when a feature that is split is controlled by its split policy.

  • DEFAULTThe attributes of the two resulting features take on the default value of the attribute of the given feature class or subtype.
  • DUPLICATEThe attribute of the two resulting features takes on a copy of the original object's attribute value.
  • GEOMETRY_RATIOThe attributes of resulting features are a ratio of the original feature's value. The ratio is based on the proportion into which the original geometry is divided. If the geometry is divided equally, each new feature's attribute gets one-half the value of the original object's attribute. The geometry ratio policy only applies to range domains.
String
merge_policy
(Optional)

The merge policy of the created domain. When two features are merged into a single feature, merge policies control attribute values in the new feature.

  • DEFAULTThe attribute of the resulting feature takes on the default value of the attribute of the given feature class or subtype. This is the only merge policy that applies to nonnumeric fields and coded value domains.
  • SUM_VALUESThe attribute of the resulting feature takes on the sum of the values from the original feature's attribute. The sum values policy only applies to range domains.
  • AREA_WEIGHTEDThe attribute of the resulting feature is the weighted average of the attribute values of the original features. This average is based on the original feature's geometry. The area weighted policy only applies to range domains.
String

Code Sample

Create Domain Example (Python Window)

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

import arcpy
from arcpy import env
env.workspace = "C:/data"
arcpy.CreateDomain_management("montgomery.gdb", "Materials", "Valid pipe materials", "TEXT", "CODED")
Create Domain Example 2 (Stand-alone Script)

This stand-alone script utilized the CreateDomain function as part of a workflow to create an attribute domain, assign values to it, and assign the domain to a field in a feature class.

# Name: MakeDomain.py
# Description: Create an attribute domain to constrain pipe material values
# Author: ESRI
 
#Import system modules
import arcpy
from arcpy import env
 
try:
    # Set the workspace (to avoid having to type in the full path to the data every time)
    env.workspace = "C:/data"
 
    # Set local parameters
    domName = "Material4"
    gdb = "montgomery.gdb"
    inFeatures = "Montgomery.gdb/Water/Distribmains"
    inField = "Material"
 
    # Process: Create the coded value domain
    arcpy.CreateDomain_management("montgomery.gdb", domName, "Valid pipe materials", "TEXT", "CODED")
    
    #Store all the domain values in a dictionary with the domain code as the "key" and the 
    #domain description as the "value" (domDict[code])
    domDict = {"CI":"Cast iron", "DI": "Ductile iron", "PVC": "PVC", \
                "ACP": "Asbestos concrete", "COP": "Copper"}
    
    # Process: Add valid material types to the domain
    #use a for loop to cycle through all the domain codes in the dictionary
    for code in domDict:        
        arcpy.AddCodedValueToDomain_management(gdb, domName, code, domDict[code])
    
    # Process: Constrain the material value of distribution mains
    arcpy.AssignDomainToField_management(inFeatures, inField, domName)
 
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

Environments

Related Topics

Licensing Information

ArcGIS for Desktop Basic: Yes
ArcGIS for Desktop Standard: Yes
ArcGIS for Desktop Advanced: Yes
11/18/2013