public FeatureClassToken Create( 
   FeatureClassDescription featureClassDescription
)

{
  // Must be called within QueuedTask.Run
  void CreateFeatureClassSnippet(Geodatabase geodatabase, FeatureClass existingFeatureClass,
    SpatialReference spatialReference)
  {
    // Create a Cities feature class with the following fields
    // GlobalID
    // ObjectID
    // Name (string)
    // Population (integer)

    // This helper routine creates a FieldDescription for a GlobalID field with default values
    FieldDescription globalIDFieldDescription = FieldDescription.CreateGlobalIDField();

    // This helper routine creates a FieldDescription for an ObjectID field with default values
    FieldDescription objectIDFieldDescription = FieldDescription.CreateObjectIDField();

    // This helper routine creates a FieldDescription for a string field
    FieldDescription nameFieldDescription = FieldDescription.CreateStringField("Name", 255);

    // This helper routine creates a FieldDescription for an integer field
    FieldDescription populationFieldDescription = FieldDescription.CreateIntegerField("Population");

    // Assemble a list of all of our field descriptions
    List<FieldDescription> fieldDescriptions = new List<FieldDescription>()
        { globalIDFieldDescription, objectIDFieldDescription, nameFieldDescription, populationFieldDescription };

    // Create a ShapeDescription object
    ShapeDescription shapeDescription = new ShapeDescription(GeometryType.Point, spatialReference);

    // Alternatively, ShapeDescriptions can be created from another feature class.  In this case, the new feature class will inherit the same shape properties of the existing class
    ShapeDescription alternativeShapeDescription = new ShapeDescription(existingFeatureClass.GetDefinition());

    // Enable support for measure (M) value, if needed
    // shapeDescription.HasM = true;

    // Enable support for the vertical coordinate system (Z), if needed
    // shapeDescription.HasZ = true;

    // Create a FeatureClassDescription object to describe the feature class to create
    FeatureClassDescription featureClassDescription =
      new FeatureClassDescription("Cities", fieldDescriptions, shapeDescription);

    // Create a SchemaBuilder object
    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Add the creation of the Cities feature class to our list of DDL tasks
    schemaBuilder.Create(featureClassDescription);

    // Execute the DDL
    bool success = schemaBuilder.Build();

    // Inspect error messages
    if (!success)
    {
      IReadOnlyList<string> errorMessages = schemaBuilder.ErrorMessages;
      //etc.
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void CreatingTableWithIndex(SchemaBuilder schemaBuilder)
  {
    FieldDescription nameFieldDescription = FieldDescription.CreateStringField("Name", 50);
    FieldDescription addressFieldDescription = FieldDescription.CreateStringField("Address", 200);

    // Creating a feature class, 'Buildings' with two fields
    TableDescription tableDescription = new TableDescription("Buildings",
      new List<FieldDescription>() { nameFieldDescription, addressFieldDescription });

    // Enqueue DDL operation to create a table
    TableToken tableToken = schemaBuilder.Create(tableDescription);

    // Creating an attribute index named as 'Idx'
    AttributeIndexDescription attributeIndexDescription = new AttributeIndexDescription("Idx", new TableDescription(tableToken),
      new List<string> { nameFieldDescription.Name, addressFieldDescription.Name });

    // Enqueue DDL operation to create an attribute index
    schemaBuilder.Create(attributeIndexDescription);

    // Execute build indexes operation
    bool isBuildSuccess = schemaBuilder.Build();
  }
}

{
  // Must be called within QueuedTask.Run
  void AddingIndexes(SchemaBuilder schemaBuilder, FeatureClassDefinition featureClassDefinition)
  {
    // Field names to add in the attribute index
    string fieldName = featureClassDefinition.GetFields().First(f => f.AliasName.Contains("Name")).Name;
    string fieldAddress = featureClassDefinition.GetFields().First(f => f.AliasName.Contains("Address")).Name;

    // Creating an attribute index with index name 'Idx' and two participating fields' name
    AttributeIndexDescription attributeIndexDescription = new AttributeIndexDescription("Idx",
      new TableDescription(featureClassDefinition), new List<string> { fieldName, fieldAddress });

    // Enqueue DDL operation for an attribute index creation 
    schemaBuilder.Create(attributeIndexDescription);

    // Creating the spatial index 
    SpatialIndexDescription spatialIndexDescription = new SpatialIndexDescription(new FeatureClassDescription(featureClassDefinition));

    // Enqueue DDL operation for the spatial index creation
    schemaBuilder.Create(spatialIndexDescription);

    // Execute build indexes operation
    bool isBuildSuccess = schemaBuilder.Build();

    if (!isBuildSuccess)
    {
      IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
      // Iterate and handle errors 
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void CreateTableWithSubtypes(SchemaBuilder schemaBuilder)
  {
    // Creating a 'Building' table with the subtype field 'BuildingType'
    FieldDescription buildingType = new FieldDescription("BuildingType", FieldType.Integer);
    FieldDescription buildingName = new FieldDescription("Name", FieldType.String);

    TableDescription tableDescription = new TableDescription("Building", new List<FieldDescription> { buildingName, buildingType });

    // Add the building type subtype with three subtypes - Business, Marketing, Security
    tableDescription.SubtypeFieldDescription = new SubtypeFieldDescription(buildingType.Name,
      new Dictionary<int, string> { { 1, "Business" }, { 2, "Marketing" }, { 3, "Security" } })
    {
      DefaultSubtypeCode = 3 // Assigning 'Security' building type as the default subtype
    };

    schemaBuilder.Create(tableDescription);
    schemaBuilder.Build();
  }
}

{
  // Must be called within QueuedTask.Run
  void CreateRelationshipWithRelationshipRules(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);
    FieldDescription usageSubType = FieldDescription.CreateIntegerField("UsageSubtype");
    FeatureClassDescription featureClassDescription = new FeatureClassDescription("Building",
      new List<FieldDescription> { buildingId, buildingAddress, buildingType, usageSubType },
      new ShapeDescription(GeometryType.Polygon, SpatialReferences.WGS84));

    // Set subtype details (optional)
    featureClassDescription.SubtypeFieldDescription = new SubtypeFieldDescription(usageSubType.Name,
      new Dictionary<int, string> { { 1, "Marketing" }, { 2, "Utility" } });

    FeatureClassToken buildingToken = schemaBuilder.Create(featureClassDescription);

    // Creating a 1:M relationship between the 'Building' feature class and 'BuildingType' table
    RelationshipClassDescription relationshipClassDescription = new RelationshipClassDescription(
      "BuildingToBuildingType", new FeatureClassDescription(buildingToken), new TableDescription(buildingtypeToken),
      RelationshipCardinality.OneToMany, buildingType.Name, buildingType.Name)
    {
      RelationshipType = RelationshipType.Composite
    };

    // Adding relationship rules for the 'Marketing' subtype
    relationshipClassDescription.RelationshipRuleDescriptions.Add(new RelationshipRuleDescription(1, null));

    schemaBuilder.Create(relationshipClassDescription);
    schemaBuilder.Build();
  }
}

{
  // Must be called within QueuedTask.Run
  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();
  }
}