ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.DDL Namespace / SchemaBuilder Class / Create Method / Create(AttributedRelationshipClassDescription) Method
Indicates the ArcGIS.Core.Data.RelationshipClass to be created.
Example Version

Create(AttributedRelationshipClassDescription) Method
Enqueue the create operation on the object referred to by the AttributedRelationshipClassDescription. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
Exceptions
ExceptionDescription
The relationship split policy, relationship rules, and/or the origin foreign key fields are invalid.
attributedRelationshipClassDescription is null.
Memory ArcGIS.Core.Data.Geodatabase does not support attributed relationship classes.
The relationship split policy is not supported.
This method or property must be called within the lambda passed to QueuedTask.Run.
Example
Creating attributed relationship class
public void CreateAttributedRelationship(SchemaBuilder schemaBuilder)
{
    // Creating a 'BuildingType' table with two fields - BuildingType and BuildingTypeDescription
    FieldDescription buildingType = FieldDescription.CreateIntegerField("BuildingType");
    FieldDescription buildingTypeeDescription = FieldDescription.CreateStringField("BuildingTypeDescription", 100);
    TableDescription buildingTypeDescription = new TableDescription("BuildingType", new List<FieldDescription>() { buildingType, buildingTypeeDescription });
    TableToken buildingtypeToken = schemaBuilder.Create(buildingTypeDescription);

    // Creating a 'Building' feature class with three fields - BuildingId, Address, and BuildingType
    FieldDescription buildingId = FieldDescription.CreateIntegerField("BuildingId");
    FieldDescription buildingAddress = FieldDescription.CreateStringField("Address", 100);
    FeatureClassDescription featureClassDescription = new FeatureClassDescription("Building", new List<FieldDescription> { buildingId, buildingAddress, buildingType }, new ShapeDescription(GeometryType.Polygon, SpatialReferences.WGS84));
    FeatureClassToken buildingToken = schemaBuilder.Create(featureClassDescription);

    // Creating M:M relationship between the 'Building' feature class and 'BuildingType' table
    AttributedRelationshipClassDescription attributedRelationshipClassDescription = new AttributedRelationshipClassDescription("BuildingToBuildingType", new FeatureClassDescription(buildingToken),
        new TableDescription(buildingtypeToken), RelationshipCardinality.ManyToMany, "OBJECTID", "BuildingID", "OBJECTID", "BuildingTypeID");

    // Adding optional attribute field in the intermediate table - 'OwnershipPercentage' field
    attributedRelationshipClassDescription.FieldDescriptions.Add(FieldDescription.CreateIntegerField("OwnershipPercentage"));

    schemaBuilder.Create(attributedRelationshipClassDescription);
    schemaBuilder.Build();
}
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3.1 or higher.
See Also