外键(新手)

Question

我想在我的反馈表中插入我的customer_id的外键。我怎么发动汽车呢？

customer表：

customer_id 
coach_id
customer_name

feedback表：

feedback_id
feedback1
feedback2
customer_id 

我想做的地方，在用户登录后，用户插入反馈信息，它将自动注册客户id。

这是我登录后的代码，希望注册反馈：

<?php
session_name ('YourVisitID');
session_start();
$page_title = 'Feedback';
include('./header4.html');
//remember to delete.
echo "{$_SESSION['customer_name']}";
?>

<section id="main" class="wrapper">
<div class="container">
<form action = "feedback.php" method="post">
<div class="row uniform 50%">
        <div class="6u 12u$(xsmall)">
        <input type="text" name="weight" placeholder="Weight" 
        required autofocus/>
        </div>
        <div class="6u$ 12u$(xsmall)">
        <input type="text" name="height" placeholder="Height" 
        required autofocus/>
        </div>
        <div class="6u 12u$(xsmall)">
        <input type="text" name="water"  placeholder="Water Level%" 
        required autofocus/>
        </div>
        <div class="6u$ 12u$(xsmall)">
        <input type="text" name="body_fat" placeholder="Body Fat%" 
        required autofocus/>
        </div>
        <div class="6u 12u$(xsmall)">
        <input type="text" name="calorie" placeholder="Calorie" 
        required autofocus/>
        </div>
        <div class="6u$ 12u$(xsmall)">
        <input type="text" name="visceral" placeholder="Visceral Fat Level%" 
        required autofocus/>
        </div>
        <p><input type="submit" name="submit" value="Register" /></p>
        <input type="hidden" name="submitted" value="TRUE" />

</div>
</form>
</div>
</section>

<?php

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

require_once ('mysql_connect3.php');

function escape_data ($data){
    global $dbc;
    if (ini_get('magic_quotes_gpc')){
    $data = stripslashes($data);
    }
    return mysql_real_escape_string(trim($data), $dbc);
    }

    $error = array();
        $weight = escape_data($_POST['weight']);
        $height = escape_data($_POST['height']);
        $water = escape_data($_POST['water']);
        $calorie = escape_data($_POST['calorie']);
        $visceral = escape_data($_POST['visceral']);
        $fat = escape_data($_POST['body_fat']);

mysqli_close($con);
header("location: add_user.php?remarks=success");   
    if (empty ($errors)) {

    $query ="SELECT * FROM feedback WHERE weight ='$weight'";
    $result = mysql_query($query);
    if (mysql_num_rows($result) == 0) {

        $query = "INSERT INTO feedback (weight, height, body_fat, water, calorie, visceral, feedback_date) VALUES 
        ('$weight', '$height', '$water', '$calorie', '$visceral','$fat', NOW() )";
        $result = @mysql_query ($query);
        if ($result) {

        echo '<script>
            alert("Your feedback has been save");
            </script>';

        include ('./footer.html');
        exit();
        }else{
            echo '<script>
            alert("<h1 id="mainhead">System Error</h1>
            <p class="error">You could not give feedback due to a system error.
            We apologize for any inconvenience.</p>");
            </script>';
            echo '<p>'. mysql_error() . '<br /><br />Query: ' . $query . '</p>';
            include ('./footer.html');
            exit();
            }
            }
                }else{
                    echo '<script>
                            alert("<h1 id="mainhead">Error!</h1>
                            <p class="error">Please try again.</p>");
                            </script>';
                        }

                        mysql_close();
                        }

?>

<?php
include ('./footer.html');
?>

Answer 1

我认为您应该在sql表模式中定义。

在feedback表中定义外键customer_id之后

您可以使用PHP从该表中选择数据

Answer 2

当客户登录时，只需将其customer_id存储在会话中，就像您当前存储其customer_name一样。当客户提交反馈表单时，您只需提供会话中的customer_id。

    $query = "INSERT INTO feedback (weight, height, body_fat, water, calorie, visceral, feedback_date, customer_id) VALUES 
    ('$weight', '$height', '$water', '$calorie', '$visceral','$fat', NOW(), ".$_SESSION ['customer_id']. ")";
    $result = @mysql_query ($query);  

以下是一些注意事项：

1. 不再使用mysql_*()函数，它们几年前就被弃用了，并且从php7开始就被删除了。使用mysqli或pdo。
2. 使用带参数绑定的预准备语句，以防止sql注入攻击。
3. 不要混用各种mysql apis。