[0] UnexpectedValueException in Builder.php line 347

tp5 往mongodb中插入數據時報錯，經查是字符編碼的關係。

數據源是sqlserver2000，查詢出來的格式是GBK，而向mongodb中插入的數據必須是utf8，所以出現了這個錯誤，轉下格式就好了

  $encode = mb_detect_encoding($v1[0], array("ASCII",'UTF-8',"GB2312","GBK",'BIG5'));
  $tmp0 = mb_convert_encoding($v1[0], 'UTF-8', $encode);//dd($tmp0);