public class FieldDescription : Description 

{
  FieldDescription bigIntegerFieldDescription =
    new FieldDescription("BigInteger_64", FieldType.BigInteger);
}

{
  // 64-bit
  FieldDescription oidFieldDescription_64 =
    new FieldDescription("ObjectID_64", FieldType.OID)
    {
      Length = 8
    };

  // 32-bit
  FieldDescription oidFieldDescription_32 =
    new FieldDescription("ObjectID_32", FieldType.OID)
    {
      Length = 4
    };
}

{
  // Earthquake occurrences date and time

  // 9/28/2014 (DateOnly)
  FieldDescription earthquakeDateOnlyFieldDescription =
    new FieldDescription("Earthquake_DateOnly", FieldType.DateOnly);

  // 1:16:42 AM (TimeOnly)
  FieldDescription earthquakeTimeOnlyFieldDescription =
    new FieldDescription("Earthquake_TimeOnly", FieldType.TimeOnly);

  // 9/28/2014 1:16:42.000 AM -09:00 (Timestamp with Offset)
  FieldDescription earthquakeTimestampOffsetFieldDescription =
    new FieldDescription("Earthquake_TimestampOffset_Local", FieldType.TimestampOffset);

  // 9/28/2014 1:16:42 AM (DateTime)
  FieldDescription earthquakeDateFieldDescription =
    new FieldDescription("Earthquake_Date", FieldType.Date);
}

{
  // Must be called within QueuedTask.Run
  void CreateFeatureDatasetWithFeatureClassSnippet(Geodatabase geodatabase)
  {
    // Creating a FeatureDataset named as 'Parcel_Information' and a FeatureClass with name 'Parcels' in one operation
    string featureDatasetName = "Parcel_Information";
    string featureClassName = "Parcels";

    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Create a FeatureDataset token
    FeatureDatasetDescription featureDatasetDescription = new FeatureDatasetDescription(featureDatasetName, SpatialReferences.WGS84);
    FeatureDatasetToken featureDatasetToken = schemaBuilder.Create(featureDatasetDescription);

    // Create a FeatureClass description
    FeatureClassDescription featureClassDescription = new FeatureClassDescription(featureClassName,
      new List<FieldDescription>()
      {
          new FieldDescription("Id", FieldType.Integer),
          new FieldDescription("Address", FieldType.String)
      },
      new ShapeDescription(GeometryType.Point, SpatialReferences.WGS84));

    // Create a FeatureClass inside a FeatureDataset
    FeatureClassToken featureClassToken = schemaBuilder.Create(
      new FeatureDatasetDescription(featureDatasetToken),
      featureClassDescription);

    // Build status
    bool buildStatus = schemaBuilder.Build();

    // Build errors
    if (!buildStatus)
    {
      IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void CreateFeatureClassInsideFeatureDatasetSnippet(Geodatabase geodatabase)
  {
    // Creating a FeatureClass named as 'Tax_Jurisdiction' in existing FeatureDataset with name 'Parcels_Information'
    string featureDatasetName = "Parcels_Information";
    string featureClassName = "Tax_Jurisdiction";

    // Create a FeatureClass description
    FeatureClassDescription featureClassDescription = new FeatureClassDescription(featureClassName,
      new List<FieldDescription>()
      {
          new FieldDescription("Tax_Id", FieldType.Integer),
          new FieldDescription("Address", FieldType.String)
      },
      new ShapeDescription(GeometryType.Point, SpatialReferences.WGS84));

    FeatureDatasetDefinition featureDatasetDefinition = geodatabase.GetDefinition<FeatureDatasetDefinition>(featureDatasetName);

    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Create a FeatureClass inside a FeatureDataset using a FeatureDatasetDefinition
    schemaBuilder.Create(new FeatureDatasetDescription(featureDatasetDefinition), featureClassDescription);

    // Build status
    bool buildStatus = schemaBuilder.Build();

    // Build errors
    if (!buildStatus)
    {
      IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
    }
  }
}

{
  // Must be called within QueuedTask.Run
  void RemoveFieldTableSnippet(Geodatabase geodatabase)
  {
    // Removing all fields from 'Parcels' table except following 
    // Tax_Code
    // Parcel_Address

    // The table to remove fields
    string tableName = "Parcels";

    TableDefinition tableDefinition = geodatabase.GetDefinition<TableDefinition>(tableName);
    IReadOnlyList<Field> fields = tableDefinition.GetFields();

    // Existing fields from 'Parcels' table
    Field taxCodeField = fields.First(f => f.Name.Equals("Tax_Code"));
    Field parcelAddressField = fields.First(f => f.Name.Equals("Parcel_Address"));

    FieldDescription taxFieldDescription = new FieldDescription(taxCodeField);
    FieldDescription parcelAddressFieldDescription = new FieldDescription(parcelAddressField);

    // Fields to retain in modified table
    List<FieldDescription> fieldsToBeRetained = new List<FieldDescription>()
      {
        taxFieldDescription, parcelAddressFieldDescription
      };

    // New description of the 'Parcels' table with the 'Tax_Code' and 'Parcel_Address' fields
    TableDescription modifiedTableDescription = new TableDescription(tableName, fieldsToBeRetained);

    SchemaBuilder schemaBuilder = new SchemaBuilder(geodatabase);

    // Remove all fields except the 'Tax_Code' and 'Parcel_Address' fields
    schemaBuilder.Modify(modifiedTableDescription);
    schemaBuilder.Build();
  }
}