PHP插入mysql数据库，其中“WHERE field”等于我的选择

Question

我需要插入新的位置与我从我的下拉列表中选择的名称行。如何在名称和位置之间建立连接？

<?php

 $connect = mysqli_connect('localhost', 'root', '', 'test');
 $query = 'SELECT * FROM test';
 $res = mysqli_query($connect, $query);

echo "<select name='testform'>";
while($row=mysqli_fetch_assoc($res)){
 echo "<option value=>$row[name]</option>";

}
echo "</select>";


 ?>

<html>
<form action="indexx.php" method="POST">
<br>Locatio name:<input type= "text" method="POST"><BR>
<input type="submit" value="Insert" method="POST">
</form>
</html>

Answer 1

检查表单是否已提交，方法是为表单命名并检查是否在PHP代码中设置了该名称。如果设置了，则表示用户提交了您的数据录入表单。使用用户输入的值执行INSERT语句。

Sidenote:输入标记没有"method“属性。您可以删除它们。

您可能想要了解PHP脚本的生命周期以及$_POST数组在PHP中的用法。INSERT语句的语法可以在许多语言规范或教程中找到。

Answer 2

我认为你把事情搞混了，并为你写了下面的代码。请告诉我这是否能更好地解释它。

您需要的代码

<?php
if (isset($_POST['submit'])) {
    $connect = mysqli_connect('localhost', 'root', '', 'test');
    $query = "UPDATE test SET location_name='".$_POST['new_location']."' WHERE id='".$_POST['location']."' LIMIT 1";
    $res = mysqli_query($connect, $query);
    if (!$res) {
        die("Something went wrong");
    }
}

// This is the code to load the select options
$connect = mysqli_connect('localhost', 'root', '', 'test');
$query = 'SELECT * FROM test';
$res = mysqli_query($connect, $query);

$options = array();
while($row = mysqli_fetch_assoc($res)) {
    $options[] = $row;
}
?>
<form method="POST" action="<?= $_SERVER['PHP_SELF'] ?>">
    <select name="location">
        <option value="0">--- Select an option ---</option>
        <?php foreach ($options as $option): ?>
            <option value="<?= $option['id'] ?>"><?= $option['name'] ?></option>
        <?php endforeach; ?>
    </select><br />
    New name: <input type="text" name="new_location"><br />
    <input type="submit" name="submit" value="Update" />
</form>

Answer 3

<?php
if (isset($_POST['submit'])) {
    $connect = mysqli_connect('localhost', 'root', '', 'test');
    $query = "UPDATE test SET location_name='".$_POST['new_location']."' WHERE id='".$_POST['location']."' LIMIT 1";
    $res = mysqli_query($connect, $query);
    if (!$res) {
        die("Something went wrong");
    }
}

// This is the code to load the select options
$connect = mysqli_connect('localhost', 'root', '', 'test');
$query = 'SELECT * FROM test';
$res = mysqli_query($connect, $query);

$options = array();
while($row = mysqli_fetch_assoc($res)) {
    $options[] = $row;
}
?>
<form method="POST" action="<?= $_SERVER['PHP_SELF'] ?>">
    <select name="location">
        <option value="0">--- Select an option ---</option>
        <?php foreach ($options as $option): ?>
            <option value="<?= $option['id'] ?>"><?= $option['name'] ?></option>
        <?php endforeach; ?>
    </select><br />
    New name: <input type="text" name="new_location"><br />
    <input type="submit" name="submit" value="Update" />
</form>