MySql.Data.MySqlClient.MySqlParameterCollection.Add C# (CSharp) Method

    public MySqlParameter Add(MySqlParameter value)
    {
      return InternalAdd(value, -1);
    }

        public static string KeyToWhere(IDataStoreKey key, MySqlParameterCollection parameters)
        {
            string where = null;

              if (key is CounterDataStoreKey)
              {
            where = "T1.COUNTER = ?CTR";
            var par = new MySqlParameter();
            par.ParameterName = "?CTR";
            par.Value = ((CounterDataStoreKey)key).Counter;

            parameters.Add(par);
              }
              else
              if (key is GDID)
              {
            where = "T1.GDID = ?CTR";
            var par = new MySqlParameter();
            par.ParameterName = "?CTR";
            par.Value = key;

            parameters.Add(par);
              }
              else
            if (key is NameValueDataStoreKey)
            {
              var dict = key as NameValueDataStoreKey;
              var s = new StringBuilder();
              var idx = 0;

              foreach (var e in dict)
              {
                s.AppendFormat(" (T1.`{0}` = ?P{1}) AND", e.Key, idx);
                var par = new MySqlParameter();
                par.ParameterName = "?P" + idx.ToString();
                par.Value = e.Value;
                parameters.Add(par);

                idx++;
              }

              if (s.Length > 0) s.Remove(s.Length - 3, 3);//cut "AND"

              where = s.ToString();
            }
            else
              throw new MySQLDataAccessException(StringConsts.INVALID_KEY_TYPE_ERROR);

              return where;
        }