php 预准备语句不显示用户数据
我设置了一个输入表单，在其中我使用 SELECT 函数在表中搜索现有用户，因此它将显示用户的姓名和电子邮件。但是当我尝试时，即使表中有一个名为John的用户，我也会得到“没有名为John的用户！”。为什么准备好的声明不起作用？添加准备语句.php
<?php
include_once 'includes/db_connect.php';
?>
<!DOCTYPE html>
<html>
<head>
<title>SCIENCE FAIR</title>
<link rel="stylesheet" href="style.css">
<section class ="container grey-text">
<form class="white" action="addpreparedstatements.php" method="POST">
<tr>
<label>First Name:</label>
<td><input type="text" name="firstname" placeholder="First Name"></td></br>
</tr>
<div class="center">
<td colspan="2"><input type="submit" name="submit" value="Submit"></td>
</div>
</form>
</section>
</html>
<?php
$firstname = mysqli_real_escape_string($conn, $_POST['firstname']);
$sql = "SELECT * FROM usersthree WHERE id=?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("s", $id);
$stmt->execute();
$result = $stmt->get_result(); // get the mysqli result
$user = $result->fetch_assoc(); // fetch data
$queryResult = mysqli_num_rows($result);
if ($queryResult > 0) {
while ($row = mysqli_fetch_assoc($result)) {
echo "<div>
<p>".$row['name']."<p>
<p>".$row['email']."<p>
</div>";
}
} else {
echo "No users with name $firstname!";
}
?>
有只小跳蛙1回答
-
慕尼黑8549860
绑定到查询的变量未初始化。$id您想要搜索“名字”，因此您需要在查询中使用变量$firstname。// Check if formular is send and $_POST['firstname'] is setif (isset($_POST['firstname'])) { // Escaping is not neccessary because you use prepared statements! $firstname = $_POST['firstname']; $sql = "SELECT * FROM usersthree WHERE firstname=?"; $stmt = $conn->prepare($sql); $stmt->bind_param("s", $firstname); $result = $stmt->get_result(); // get the mysqli result $queryResult = mysqli_num_rows($result); if ($queryResult > 0) { while ($row = mysqli_fetch_assoc($result)) { echo "<div> <p>".$row['name']."<p> <p>".$row['email']."<p> </div>"; } } else { echo "No users with name $firstname!"; }}
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