[SgFunctionHost]
  public interface ISystemDbFunctions
  {
    [DbComposableFunction("SYS3.fn_DateToShamsiDate")]
    string DateToShamsiDate([DbType(FieldType.DateTime)] DateTime? date);

    [DbComposableFunction("SYS3.fn_DateToShamsiDate")]
    string DateToShamsiDateTime([DbType(FieldType.DateTime)] DateTime? date);

    [DbComposableFunction("SYS3.fnAddPersianMonth")]
    DateTime? AddPersianMonth([DbType(FieldType.DateTime)] DateTime? date, [DbType(FieldType.Int)] int? monthes);

    [DbComposableFunction("SYS3.fnAddPersianYear")]
    DateTime? AddPersianYear([DbType(FieldType.DateTime)] DateTime? date, [DbType(FieldType.Int)] int? years);
  }