$sql="select sum(num) as totalnum from $table where product='a' ";
$result=mysql_query($sql);
$obj=mysql_fetch_object($result);
$x=$obj->totalnum;
echo $x;
$result=mysql_query($sql);
$obj=mysql_fetch_object($result);
$x=$obj->totalnum;
echo $x;
$sql="select sum(num) as totalnum from $table where product='a' ";
$result=mysql_query($sql);
$obj=mysql_fetch_object($result);
$x=$obj["totalnum"]
echo $x;
$sql="select sum(num) as totalnum from $table where product='a' ";
$result=mysql_query($sql);
$obj=mysql_fetch_array($result);
$x=$obj["totalnum"]
echo $x;
如果需要求每个类别的总合使用SELECT SUM( `num` ) AS totalnum FROM `ss` GROUP BY `name`$sql="SELECT SUM( `num` ) AS totalnum FROM `$table` GROUP BY `name`";
$result=mysql_query($sql);for($i=0; $i<3; $i++) {
$row=mysql_fetch_assoc($result);
$x=$row['totalnum'];
echo $x,"<br/>";
}
$sql="SELECT `product`, SUM( `num` ) AS totalnum FROM `$table` GROUP BY `product`";
$result=mysql_query($sql);for($i=0; $i<3; $i++) {
$row=mysql_fetch_assoc($result);
$x=$row['product'];
$y=$row['totalnum'];
echo $x,$y,"<br/>";
}