Add Relate (Data Management)

Summary

Relates a layer to another layer or table based on a field value. Feature layers, table views, subtype value layers or tables, and raster layers with a raster attribute table are supported.

The records in the Relate Table parameter value are matched to the records in the input Layer Name or Table View parameter value. A match occurs when a field value in the Input Relate Field parameter value and a field value in the Output Relate Field parameter value are equal.

Usage

• If the input is a feature class or dataset path, this tool will create and return a new layer with the result of the tool applied.

• A relate does not modify data; a relate is a property of the layer or table view.

• Records from the relate table can be matched to more than one record in the input layer or table view.

• The relate table can be a geodatabase table or a dBASE file. The relate table does not have to be a layer.

• The input must have an Object ID field. The relate table is not required to contain an Object ID field.

• To save the relate for use in another project, save the layer to a layer file using the Save Layer To File tool. This only applies to layers; table views cannot be saved in this manner.

• To make a permanent relate, use the Create Relationship Class tool.

• Indexing the fields in the input layer or table view and the relate table on which the relate will be based can improve performance. This can be done with the Add Attribute Index tool.

• When the input layer has a relationship and the Automatically select related data property is checked, a selection on the input layer will also select records in the related table.

Parameters

Dialog

Label	Explanation	Data Type
Layer Name or Table View	The layer or table view to which the relate table will be related.	Mosaic Layer; Raster Layer; Table View
Input Relate Field	The primary key field in the input layer or table view on which the relate will be based.	Field
Relate Table	The table or table view to be related to the input layer or table view.	Mosaic Layer; Raster Layer; Table View
Output Relate Field	The foreign key field in the relate table that will be used to match the primary key.	Field
Relate Name	The unique name of a relate.	String
Cardinality (Optional)	Specifies the cardinality of the relationship. One to one—The relationship between the input table and related table will be one to one. For example, one record in the input table will have only one matching record in the related table. One to many—The relationship between the input table and related table will be one to many. For example, one record in the input table can have multiple matching records in the related table. This is the default. Many to many—The relationship between the input table and related table will be many to many. For example, many records with the same value in the input table can have multiple matching records in the related table.	String

Derived Output

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

Python

arcpy.management.AddRelate(in_layer_or_view, in_field, relate_table, relate_field, relate_name, {cardinality})

Name	Explanation	Data Type
in_layer_or_view	The layer or table view to which the relate table will be related.	Mosaic Layer; Raster Layer; Table View
in_field	The primary key field in the input layer or table view on which the relate will be based.	Field
relate_table	The table or table view to be related to the input layer or table view.	Mosaic Layer; Raster Layer; Table View
relate_field	The foreign key field in the relate table that will be used to match the primary key.	Field
relate_name	The unique name of a relate.	String
cardinality (Optional)	Specifies the cardinality of the relationship. ONE_TO_ONE—The relationship between the input table and related table will be one to one. For example, one record in the input table will have only one matching record in the related table. ONE_TO_MANY—The relationship between the input table and related table will be one to many. For example, one record in the input table can have multiple matching records in the related table. This is the default. MANY_TO_MANY—The relationship between the input table and related table will be many to many. For example, many records with the same value in the input table can have multiple matching records in the related table.	String

Derived Output

Name	Explanation	Data Type
out_layer_or_view	The updated input dataset.	Table View; Raster Layer; Mosaic Layer

Code sample

AddRelate example 1 (Python window)

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

import arcpy
arcpy.management.AddRelate("Parcel", "ParcelID", "owner_table", "ParcelID", 
                           "Owner2Parcel")

Environments

Current Workspace