PHP/MySQL忽略小数点右边的数字

Question

我编写了一段代码，让用户可以从两个选项中选出一个来投票，然后使用修改后的 Elo 评分系统计算分数。但是，当我投票给其中一个选项时，小数点右边的数字将被忽略。我添加了 floatval 函数，但没有帮助。

$query = "SELECT pic,score,id FROM nfl
    JOIN (SELECT r1.random_id
         FROM nfl_map AS r1
         JOIN (SELECT (RAND() *
                      (SELECT MAX(row_id)
                         FROM nfl_map)) AS row_id)
               AS r2
        WHERE r1.row_id >= r2.row_id
        ORDER BY r1.row_id ASC
        LIMIT 1) as rows ON (id = random_id)";

    $query_2 = "SELECT pic,score,id FROM nfl
    JOIN (SELECT r1.random_id
         FROM nfl_map AS r1
         JOIN (SELECT (RAND() *
                      (SELECT MAX(row_id)
                         FROM nfl_map)) AS row_id)
               AS r2
        WHERE r1.row_id >= r2.row_id
        ORDER BY r1.row_id ASC
        LIMIT 1) as rows ON (id = random_id)";
    $res_2 = $mysqli->query($query_2);
    if (!$res_2) die ("Result display failed: " . $mysqli->errno . " - " . $mysqli->error);
    $pic_2 = $res_2->fetch_assoc();
    $id_2 = $res_2->fetch_assoc();
    $score_2 = $res_2->fetch_assoc();


    $res_1 = $mysqli->query($query);
    if (!$res_1) die ("Result display failed: " . $mysqli->errno . " - " . $mysqli->error);
    $pic_1 = $res_1->fetch_assoc();
    $id_1 = $res_1->fetch_assoc();
    $score_1 = $res_1->fetch_assoc();
    $Ra = $score_1;
    $Rb = $score_2;
    $calc_pow_1 = (($Rb - $Ra) / 400);
    $calc_pow_2 = (($Ra - $Rb) / 400);
    $float_calc_pow_1 = floatval($calc_pow_1);
    $float_calc_pow_2 = floatval($calc_pow_2);
    $Ea = 1 / (1 + pow(10,$float_calc_pow_1));
    $Eb = 1 / (1 + pow(10,$float_calc_pow_2));
    $float_Ea = floatval($Ea);
    $float_Eb = floatval($Eb);

    // if user votes for picture no. 1
    if (isset($_POST['vote_1']) && isset($_POST['id']) && isset($_POST['score']))
    {
    $id = $_POST['id'];
    /* $score = $_POST['score'];
    $pic = $_POST['pic']; */
    //$mod = 2 * $Eb;
    $K = 4;
    $float_mod_1 = floatval($K * (1 - $float_Ea));

    $query = "UPDATE nfl SET score=?+$float_mod_1 WHERE id=?";
    // $score_new = $_POST['score'] + $mod;
    $score_new = $_POST['score'] + $float_mod_1;

    $stmt = $mysqli->prepare($query);
    $stmt->bind_param('di', $_POST['score'], $_POST['id']);
    $stmt->execute();
    if ($stmt->errno) {
        echo "Vote failed: " . $stmt->error();
    }
    else echo "Vote succeeded! New score of $id_1 is $score_new!<br/><br/>";
    $stmt->close();
    }

    // fetch picture no. 2
    // 
    // query to the database
    /* $query_2 = "SELECT pic,score,id FROM nfl
    JOIN (SELECT r1.random_id
         FROM nfl_map AS r1
         JOIN (SELECT (RAND() *
                      (SELECT MAX(row_id)
                         FROM nfl_map)) AS row_id)
               AS r2
        WHERE r1.row_id >= r2.row_id
        ORDER BY r1.row_id ASC
        LIMIT 1) as rows ON (id = random_id)";
    $res_2 = $mysqli->query($query_2);
    if (!$res_2) die ("Result display failed: " . $mysqli->errno . " - " . $mysqli->error);
    $pic_2 = $res_2->fetch_assoc();
    $id_2 = $res_2->fetch_assoc();
    $score_2 = $res_2->fetch_assoc(); */

    // if user votes for picture no. 2
    if (isset($_POST['vote_2']) && isset($_POST['id']) && isset($_POST['score']))
    {
    $id = $_POST['id'];
    /* $score = $_POST['score'];
    $pic = $_POST['pic']; */
    //$mod = 2 * $Ea;
    $K = 4;
    $float_mod_2 = floatval($K * (1 - $float_Eb));

    $query = "UPDATE nfl SET score=?+$float_mod_2 WHERE id=?";
    // $score_new = $_POST['score'] + $mod;
    $score_new = $_POST['score'] + $float_mod_2;

    /*  $query = "UPDATE nfl SET score=?+1 WHERE id=?";
    $score_new = $_POST['score'] + $mod; */

    $stmt = $mysqli->prepare($query);
    $stmt->bind_param('di', $_POST['score'], $_POST['id']);
    $stmt->execute();
    if ($stmt->errno) {
        echo "Vote failed: " . $stmt->error();
    }
    else echo "Vote succeeded! New score of $id_2 is $score_new!<br/><br/>";
    $stmt->close();
    }

这是完整的代码，如果您需要查看:http://snipt.org/vDhj2

处理用户投票给第二个选项的情况的代码几乎相同(除了 $Ea 更改为 $Eb 等)。 MySQL 中 'score' 行的属性如下:

float(8,3) not null

谢谢。

编辑:我不再收到通知了。

Answer 1

我认为您只是错过了代码中的声明:

$res_1 = $mysqli->query($query);
if (!$res_1) die ("Result display failed: " . $mysqli->errno . " - " . $mysqli->error);
$pic_1 = $res_1->fetch_assoc();
$id_1 = $res_1->fetch_assoc();
$score_1 = $res_1->fetch_assoc();
$Ra = $score_1;
$Rb = $score_2;

我看不到上面代码中任何地方定义的 $score_2，您试图将它的值分配给另一个变量。

警告是有原因的 - 忽略它们是一个坏主意，因为它不可避免地会导致您的代码出错。在这种情况下，您只需在分配变量之前声明您的变量(即使它是 si,ply $score_2=0; 如果这是默认值，但仍然分配它。