/// <summary>
 /// Execute scalar to...
 /// </summary>
 /// <param name="conn"></param>
 /// <param name="cmdText"></param>
 /// <param name="transaction"></param>
 /// <typeparam name="T"></typeparam>
 /// <returns></returns>
 public static T ExecuteScalarTo <T>(this NpgsqlConnection conn, string cmdText, NpgsqlTransaction transaction)
 {
     conn.CheckNull(nameof(conn));
     return(conn.ExecuteScalarTo <T>(cmdText, null, CommandType.Text, transaction));
 }
 /// <summary>
 /// Execute scalar to...
 /// </summary>
 /// <param name="conn"></param>
 /// <param name="cmdText"></param>
 /// <param name="parameters"></param>
 /// <param name="commandType"></param>
 /// <typeparam name="T"></typeparam>
 /// <returns></returns>
 public static T ExecuteScalarTo <T>(this NpgsqlConnection conn, string cmdText, NpgsqlParameter[] parameters, CommandType commandType)
 {
     conn.CheckNull(nameof(conn));
     return(conn.ExecuteScalarTo <T>(cmdText, parameters, commandType, null));
 }