一个小问题 在线请求解答

[代码源]

$query = "select ncc from City";
$result=mysql_query($query);
while(list($ncc) = mysql_fetch_row($result)){
$a=$ncc.',';
//echo $a;
}
$string="$a";
我希望将所有数据库的ncc数值全部传给$a 让$string＝"所有ncc"；如何实现 谢谢了

[一起混吧]

$a-'';
while(list($ncc) = mysql_fetch_row($result)){
$a.=$ncc;
}
$string=$a;

[piaolankeke]

$a = '';
$query = "select ncc from City";
$result=mysql_query($query);
while(list($ncc) = mysql_fetch_row($result)){
$a .=$ncc.',';
//echo $a;
}
$string="$a";

[一起混吧]

少了个等号：
$a='';
while(list($ncc) = mysql_fetch_row($result)){
$a.=$ncc;
}
$string=$a;

[xuzuning]

while(list($ncc[]) = mysql_fetch_row($result));
array_pop($ncc);
$string = join(',', $ncc);