使用PHP中的MySQL获取函数计算表中2个字段的总和

I have a table having the following fields: id(Autoincrement/Primary Key)/Integer1/Integer2/Sum/Product). I have filled integer1 and integer2 with the following code:

    for ($i=1;$i<=1000;$i++)
{
    $x2=rand(0,100);
    $x3=rand(0,100);
    $sql="INSERT INTO data(integer1,integer2) VALUES ($x2,$x3)";
$conn->query($sql);     
}

I need help to prepare a function which uses MySQLFetch and computes sum of integer1 and integer2 and assigns the value in sum and product. I know it can be done using a simple loop, but would really like to get an understanding of fetching data.

Assuming you are using mysqli which is how it appears with the use of $conn->query() then this might be of interest.

/* establish db connection */
$dbhost =   'localhost';
$dbuser =   'root'; 
$dbpwd  =   'xxx'; 
$dbname =   'xxx';
$conn   =   new mysqli( $dbhost, $dbuser, $dbpwd, $dbname );

/* select records to to perform sum & product upon */
$sql='select * from `data`';
$res=$conn->query( $sql );
if( $res ){

    /* prepare a new sql statement to update db records */
    $sql='update `data` set `sum`=?, `product`=? where `id`=?;';
    $stmt=$conn->prepare( $sql );

    while( $rs=$res->fetch_object() ){
        /* make some variables with records for each record */
        $id=$rs->id;
        $int_1=$rs->integer1;
        $int_2=$rs->integer2;

        /* basic maths operations */
        $sum=$int_1+$int_2;
        $product=$int_1 * $int_2;

        /* bind the variables into declared statement & execute */
        $stmt->bind_param( 'iii', $sum, $product, $id );
        $stmt->execute();
    }
    /* tidy up */
    $stmt->close();
    $conn->close();
}

 $query = "SELECT * FROM data";
 $row = mysql_query($query);
 while($result = mysql_fetch_assoc($row))
 {
   $id = $result['id'];
   $integer1 = $result['integer1'];
   $integer2 = $result['integer2'];
   $sum = $integer1 + $integer2;
   $prod = $integer1 * $integer2;
   mysql_query("UPDATE data SET sum=$sum,product=$prod WHERE id=$id");
 }

Kindly try the following example :

$db = new mysqli('localhost', 'root', 123456, 'data');

$query = 'SELCT * FROM tableName';
$objResult = $db->query($query);
while ($resultRow = $objResult->fetch_object()) {
    $id = $resultRow->id;
    $integer1 = $resultRow->integer1;
    $integer2 = $resultRow->integer2;
    $result = sumProduct($integer1, $integer2);
    $sum = $result[0];
    $product = $result[1];

    $query = "UPDATE tableName SET 
                sum = '$sum',
                product = '$product'
              WHERE
                id = $id";
    $db->query($query);
    $db->close();
}

function sumProduct($int1, $int2) {
    $sum = $int1 + $int2;
    $product = $int1 * $int2;
    return array($sum, $product);
}

Is this way you expected?