/// <summary>
        /// 获取主用户
        /// </summary>
        /// <param name="accountDb"></param>
        /// <param name="context"></param>
        /// <returns></returns>
        private TwitterAccount GetMasterAccount(string accountDb, SqliteContext context)
        {
            var accountid = FindAccountId(accountDb);

            var res = context.Find(new SQLiteString(String.Format("SELECT * FROM users WHERE user_id = '{0}'", accountid)));

            if (res.IsValid())
            {
                return(TwitterAccount.DyConvert(res.First()));
            }
            else
            {
                return(new TwitterAccount()
                {
                    UserId = accountid
                });
            }
        }
 /// <summary>
 /// 获取所有用户
 /// </summary>
 /// <param name="context"></param>
 /// <returns></returns>
 private List <TwitterAccount> GetAllTwitterAccount(SqliteContext context)
 {
     return(context.Find(new SQLiteString("SELECT * FROM users")).Select(d => TwitterAccount.DyConvert(d)).Cast <TwitterAccount>().ToList());
 }