从更新的数据库中检索数据

Question

我已经计算了 BMI，如果用户变高或变矮，我可以更新身高（很快就会更新体重）。问题是，在我已经更新身高后，我无法更新 BMI 和 BMI STATUS（体重过轻、正常、肥胖），这对我来说是个大问题..

这是我对 php

的编码

if(!isset($_SESSION['user']))
{
    header("Location: PHOME.php");
}

$res=mysql_query("SELECT * FROM users WHERE user_id=".$_SESSION['user']);
$userRow=mysql_fetch_array($res);

if(isset($_POST['updateH']))
{

    $height = $_POST['height'];
    $weight = $_SESSION['user'];
    $sex = $_SESSION['user'];
    $bmiresult = $_SESSION['user'];
    $bmi = $weight/(($height/100)*($height/100));

    if ($sex=="female")
    {
        if ($bmi <= 19)
            $bmiresult="underweight!";
        else if ($bmi>19 && $bmi<= 25)
            $bmiresult="normal";
        else if ($bmi > 25 && $bmi<= 30)
            $bmiresult="overweight!";
        else if ($bmi>30) 
            $bmiresult="OBESE!";
    }
        else if ($sex=="male")
    {
        if ($bmi <= 20)
            $bmiresult="underweight!";
        else if ($bmi>20 && $bmi<= 25)
            $bmiresult="normal";
        else if ($bmi > 25 && $bmi<= 30)
            $bmiresult="overweight!";
        else if ($bmi>30) 
            $bmiresult="OBESE!";
    }

    $sql = "UPDATE users SET height = $height, weight = $weight,
                             bmi = $bmi, bmiresult = '$bmiresult' 
            WHERE user_id=" . $_SESSION['user'];

    $result=mysql_query($sql); 

    // if successfully insert data into database, displays message "Successful". 
    if($result){ 
        echo "<script type='text/javascript'>alert('Update Successfully!')</script>";
    } else { 
        echo mysql_error();
    }
}

这是我正在使用的表格bootstrap

<form method="post" action="<?php $_PHP_SELF ?>">

<h3> Height : <?php echo $userRow['height']; ?>&nbsp; cm</h3> 
    <input type="text" class="small" name="height" id="height" placeholder="Update Height CM"/>
<button type="submit" class="btn btn-warning" name="updateH"> UPDATE </button>

Answer 1

您似乎正试图从 SESSION 中获取有关用户的所有信息，但我认为该信息不存在。但是，您从数据库中读取了用户的当前数据，因此在 $userRow 中所有现有值都可供您使用，因此使用这些值，您的计算可能会起作用。

旁注：确保会话已经启动，并且对于所有使用会话的页面。

if(!isset($_SESSION['user']))
{
    header("Location: PHOME.php");
    exit; // stop further execution
}

$res=mysql_query("SELECT * FROM users WHERE user_id=".$_SESSION['user']);
if ( ! $res ) {
    echo 'cannot find user ' . mysql_error();
}
$userRow=mysql_fetch_array($res);

if(isset($_POST['updateH']))
{
    // if new data is supplied in $_POST use it, 
    // otherwise use the existing userRow values

    $height = isset($_POST['height']) ? $_POST['height'] : $userRow['height'];
    $weight = isset($_POST['weight']) ? $_POST['weight'] : $userRow['weight'];

    $sex = $userRow['sex'];
    $bmiresult = $userRow['bmiresult '];

    //recalc BMI
    $bmi = $weight/(($height/100)*($height/100));

    if ($sex=="female")
    {
        if ($bmi <= 19)
            $bmiresult="underweight!";
        else if ($bmi>19 && $bmi<= 25)
            $bmiresult="normal";
        else if ($bmi > 25 && $bmi<= 30)
            $bmiresult="overweight!";
        else if ($bmi>30) 
            $bmiresult="OBESE!";
    }
        else if ($sex=="male")
    {
        if ($bmi <= 20)
            $bmiresult="underweight!";
        else if ($bmi>20 && $bmi<= 25)
            $bmiresult="normal";
        else if ($bmi > 25 && $bmi<= 30)
            $bmiresult="overweight!";
        else if ($bmi>30) 
            $bmiresult="OBESE!";
    }

    $sql = "UPDATE users ".
       "SET height = $height ".
       "SET bmi = $bmi".
       "SET bmiresult = $bmiresult".
       "WHERE user_id=".$_SESSION['user'];
    $result=mysql_query($sql); 

    // if successfully insert data into database, displays message "Successful". 
    if($result){ 
        echo "<script type='text/javascript'>alert('Update Successfully!')</script>";
    } else {
        echo mysql_error();
    }
}

As you are obviously just starting out on your PHP journey, please do not waste your time learning the mysql_ database extension as it is soon to be removed from PHP. Instead, spend your time learning either the mysqli_ or PDO extensions. See here for help deciding which Its quite a good read.

Answer 2

您的更新声明应为：

  $sql = "UPDATE users ".
       "SET height = $height ".
       " , bmi = $bmi".
       " , bmiresult = $bmiresult".
       "WHERE user_id=".$_SESSION['user'];
    $result=mysql_query($sql);

从更新的数据库中检索数据

retrieve data from database that is updated

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