Question

我无法从数据库表中检索数据。请帮助我）错误太多了。无法从数据库中获取任何数据

&nbsp<input type="checkbox" name="model" value="Jetta" />Jetta
<input type="checkbox" name="model" value="Laguna" />Laguna
<input type="checkbox" name="model" value="Focus" />Focus
<input type="checkbox" name="model" value="Tico" />Tico
<input type="checkbox" name="model" value="Avensis" />Avensis

<input type="submit" name="submit" value="Register" /> </div>   
<input type="hidden" name="submitted" value="TRUE"/>
</fieldset>

file=(test2.php)

<?      
  mysql_connect("localhost","root","");
        mysql_select_db("carforsale");

        $sql =mysql_query("SELECT * FROM carforsale");  
        $row=mysql_fetch_assoc($sql);       
        $manufacturerName = 'manufacturerName';
        $modelName = 'modelName';
        $acquisitionPrice = 'acquisitionPrice';

$model = $_POST['model'];
if ($model=="Jetta") {

include('connect.php');
$result = mysql_query("manufacturerName,modelName,acquisitionPrice FROM  
carforsale WHERE modelName='Jetta'");
while($row = mysql_fetch_array($result))
{
echo '<td>'. $row['manufacturerName'].' </td>';
echo '<td>'.$row['modelName'].'</td>';
echo '<td>'.$row['acquisitionPrice'].'</td>';
echo '</tr>';
}
elseif ($model=="Laguna")

$result = mysql_query("manufacturerName,modelName,acquisitionPrice FROM  
carforsale WHERE modelName='Laguna'");
while($row = mysql_fetch_array($result))        {
echo '<td style="border-left: 1px solid #eacae7;">'. 
$row['manufacturerName'].'</td>';
echo '<td>'.$row['modelName'].'</td>';
echo '<td>'.$row['acquisitionPrice'].'</td>'; 
echo '</tr>';
}
}

＆GT;

*我无法从数据库表中检索数据。请帮助我有太多的错误;＆＃39;（

Answer 1

你有条件

if ($model=="Jetta") {...

但$ model未被分配到任何地方

将其更改为

$model = $_POST['model'];
if ($model=="Jetta") {

由于没有分配，条件是假的，你在底部的else中没有任何东西可以做，所以它基本上什么都不做

Answer 2

您的代码将被分散，尝试在更逻辑的块中重构您的代码。此外，mysql_*功能还有不再支持，它们为officially deprecated，不再维护，并且将来会removed 。您应该使用PDO或MySQLi更新代码，以确保将来的项目功能。

您希望实现的更精细版本

connect.php

<?php
    $host = '127.0.0.1';
    $user = 'root';
   $pass = '';
   $database = 'blub';

    try { 
        $pdo = new PDO('mysql:host=' . $host . ';dbname=' . $database, $user, $pass);
    }catch(PDOException $e) {
        echo 'Could not connect to database: ' . $e->getMessage();
        exit;
    }

cars.php

<?php
    include('connect.php'); //only connect once

    $sql = 'SELECT * FROM carforsale'; //default query
    $parms = array();
    $parameters = '';

    if (isset($_POST['model'])) {
        $sql .= ' WHERE modelName IN ({parameters})'; //adjust query when checkbox was selected
       foreach($_POST['model'] as $checkbox) {
        $parms[] = $checkbox;
        $parameters. = '?,';//forsee a placeholder for this checkbox
    }
        $parameters =      rtrim($parameters, ',');//remove last comma from ?,?,?, 
        $sql = str_replace('{parameters}', $parameters);//inject parameters when needed
    try {
        $stmt = $pdo->prepare($sql); //use PDO with prepared statements instead of mysql_query (see comment above)
        $stmt->execute($parms); //inject the model name in the parameter ? in the sql if needed
        $rows = $stmt->fetchAll(PDO::FETCH_ASSOC);
    }catch(PDOException $e) {
        echo 'Query failed: ' . $e->getMessage(); //always check SQL errors
        exit;
    }

    $table  = '<table border="1">';
    $table .= '<tr><th>Manufacturer</th><th>Model</th><th>Price</th></tr>';
    foreach($rows as $row) {
            $table .= '<tr>';
            $table .= '<td>'. $row['manufacturerName'].' </td><td>'.$row['modelName'].'</td><td>'.$row['acquisitionPrice'].'</td>';
            $table .= '</tr>';
    }
    $table .= '</table>';
?>
<!DOCTYPE html>
<html>
    <head>
        <title>Cars</title>
    </head>
    <body>
        <form action="#" method="POST">
            <fieldset>
                <input type="checkbox" name="model[]" value="Jetta" />Jetta
                <input type="checkbox" name="model[]" value="Laguna" />Laguna
                <input type="checkbox" name="model[]" value="Focus" />Focus
                <input type="checkbox" name="model[]" value="Tico" />Tico
                <input type="checkbox" name="model[]" value="Avensis" />Avensis

                <input type="submit" name="submit" value="Register" /> </div>   
                <input type="hidden" name="submitted" value="TRUE"/>
            </fieldset>
        </form>
        <?= $table ?>
    </body>
</html>

从表单单选按钮检索数据库PHP

2 个答案:

connect.php

cars.php