1、使用mysql_fetch_field
$query=$db->query(" SELECT * FROM $tablename limit 1");
$num=mysql_num_fields($query);2、使用show fields
$sqlr="show fields from $tablename";
$query=mysql_query($sqlr);
while($row=mysql_fetch_array($query))
{
print_r($row);
$data[]=$row['Field'];
}