【发布时间】：2020-01-16 21:50:22
【问题描述】：
所以这个网站的想法是，当你按下按钮时，它会从数据库中删除相应的行。但是，我的代码的问题是，在第一次按下按钮后会填充 id 变量，然后在下一次按下时执行 php。我怎样才能避免这种情况并让他在第一次按下按钮时适应并执行 php？
包括嵌入了 php 的 HTML 页面：
<!doctype html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.4.1/js/bootstrap.min.js"></script>
<title>Untitled Document</title>
<style>
table {
font-family: arial, sans-serif;
border-collapse: collapse;
width: 100%;
}
td, th {
border: 1px solid #dddddd;
text-align: left;
padding: 8px;
}
tr:nth-child(even) {
background-color: #dddddd;
}
</style>
</head>
<body>
<div class="container-fluid">
<h2 style"text-align:center";>Please enter the item you want to add to the list below </h2>
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "myDB";
$sql = "CREATE DATABASE myDB";
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "CREATE TABLE freezerinventory (
id INT AUTO_INCREMENT PRIMARY KEY,
item VARCHAR(30) NOT NULL,
reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)";
if(isset($_POST['itemx']))
{
$itemvar = $_POST["itemx"];
$sql = "INSERT INTO freezerinventory (item)
VALUES ('$itemvar')";
$add = mysqli_query($conn, $sql);
}
else {
$sql = "";
}
mysqli_close($conn);
?>
<form action="<?=$_SERVER['PHP_SELF'];?>" class="needs-validation" novalidate method="post">
<div class="form-group">
<label for="uname"></label>
<input type="text" class="form-control" id="itemx" placeholder="Enter an item for the freezer here" name="itemx" required>
<div class="valid-feedback">Valid.</div>
<div class="invalid-feedback">Please fill out this field.</div>
</div>
<button id = "SubmitButton" name = "SubmitButton" type="button submit" class="btn btn-primary">Add to list</button>
</form>
</div>
<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "myDB";
$aVar = mysqli_connect('localhost','root','','myDB');
$conn = new mysqli($servername, $username, $password, $dbname);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "SELECT * FROM freezerinventory";
$result = mysqli_query($aVar, $sql);
echo "<table><tr>
<th>Item name</th>
<th>Date added</th>
<th>remove</th>
</tr> ";
while($row = mysqli_fetch_array($result)) {
echo " <tr><td>" . $row['item'] . "</td><td>" . $row['reg_date'] . "</td><td><form action='
' method='POST'>
<div class= 'input-group' > <div class='input-group-append'>
<button class='btn btn-danger' onclick='deleteitem()' id = 'delete' type='submit'>Remove</button>
<input type='hidden' name='id' value=".$row['id']." />
</div></div>
</form></td></tr>";
}
echo "</table>";
?>
<script>
function deleteitem (e) {
e.preventDefault();
<?php
$id = $_POST['id'];
$delete = "DELETE FROM freezerinventory WHERE id=$id";
$del = mysqli_query($conn, $delete);
?>
}
else {
}
</script>
<script>
function myFunction() {
confirm("I am an alert box!");
}
</script>
<script>
(function() {
'use strict';
window.addEventListener('load', function() {
// Get the forms we want to add validation styles to
var forms = document.getElementsByClassName('needs-validation');
// Loop over them and prevent submission
var validation = Array.prototype.filter.call(forms, function(form) {
form.addEventListener('submit', function(event) {
if (form.checkValidity() === false) {
event.preventDefault();
event.stopPropagation();
}
form.classList.add('was-validated');
}, false);
});
}, false);
})();
</script>
</body>
</html>
【问题讨论】：
-
你尝试过使用 ajax 吗？
-
你用错了ajax代码！您的代码都在同一页面中，因此，如果您不介意重新加载页面，则不需要 ajax 或 javascript，摆脱所有仅保留 php 的代码，命名要删除的按钮并检查是否使用 if 语句单击了按钮。如果单击删除按钮，则进行查询。看这里的例子：stackoverflow.com/questions/28915637/… 重要的是你对 sql 注入很开放，使用准备好的语句来防止 sql 注入
-
我一直在使用嵌入式 php，否则 GET 或 POST 函数会将我重定向到 php 页面。如何在不重定向到 php 页面的情况下执行 php？
标签： javascript php html mysql