我试图通过添加已存在的原始数字值来更新我的数据库中的字段.我有一个系统,员工可以登录并更新普通用户的余额.目前我有一个测试用户和工作人员.用户余额设置为100.我有以下代码:
<?php
if(isset($_POST['search'])){
$searchq = $_POST['search'];
$searchq = preg_replace("#[^0-9a-z]#i","",$searchq);
$result = $mysqli->query( "SELECT * FROM Users WHERE Username ='$searchq'");
if ($result){
//fetch result set as object and output HTML
if($obj = $result->fetch_object())
{
echo '<div class="booksearched">';
echo '<form method="POST" id = "books" action="">';
echo '<div class="book-content"><h3>Student Username: '.$obj->Username.'</h3>';
echo '<br>';
echo '<div class="book-content"><i>First Name: <b>'.$obj->FirstName.'</b></i></div>';
echo '<div class="book-desc"><i>Last Name:<b> '.$obj->LastName.'</b></i></div>';
echo '<br>';
echo '<div class="book-qty"> Current Balance<b> '.$obj->Balance.'</b></div>';
echo 'New Balance: <input type="number" name="newBalance" value = "1" min = "1" />';
echo '<br><br>';
echo '<button name="submit_btn" class="save_order">Top Up</button>';
echo '</div>';
echo '</form>';
echo '</div>';
}
}
}
$newBalance="";
$newBalance = $_POST['newBalance'];
if(isset($_POST['submit_btn']) ){
$upsql = "UPDATE users SET Balance = Balance + '$newBalance' WHERE Username='" . $obj->Username . "'";
$stmt = $mysqli->prepare($upsql);
$stmt->execute();
}
?>
香港专业教育学院尝试了一些事情,但我一直收到错误说:
( ! ) Notice: Undefined index: newBalance
我不确定我做错了什么.知道怎么解决吗？
编辑:完整代码
<?php
session_start();
include_once("config.php");
?>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Search</title>
<link href="style/style.css" rel="stylesheet" type="text/css">
</head>
<body>
<br>
<div id="books-wrapper">
<!-- #content to center the menu -->
<div id="content">
<!-- This is the actual menu -->
<ul id="darkmenu">
<li><a href="adminHome.php">Home</a></li>
<li><a href="addBook.php">New Books</a></li>
<li><a href="adminSearch.php">Search</a></li>
<li><a href="updateBalance.php">Update Balance</a></li>
</ul>
</div>
<div id = "welcome" >
Welcome, <?=$_SESSION['Username'];?>! <br> <a href="logout.php">Logout</a>
</div>
<br><br>
<h1 id = "mainHeader" >Update a Students Balance</h1>
<br>
<div id = "balanceupdate">
<form id = "adsearch" action="updateBalance.php" method="post">
<input type="text" name ="search" placeholder="Search For a Student">
<button name="submit" value="search">Search</button>
</form>
<br>
</div>
<?php
if(isset($_POST['search'])){
$searchq = $_POST['search'];
$searchq = preg_replace("#[^0-9a-z]#i","",$searchq);
$result = $mysqli->query( "SELECT * FROM Users WHERE Username ='$searchq'");
if ($result){
//fetch result set as object and output HTML
if($obj = $result->fetch_object())
{
echo '<div class="booksearched">';
echo '<form method="POST" id = "books" action="">';
echo '<div class="book-content"><h3>Student Username: '.$obj->Username.'</h3>';
echo '<br>';
echo '<div class="book-content"><i>First Name: <b>'.$obj->FirstName.'</b></i></div>';
echo '<div class="book-desc"><i>Last Name:<b> '.$obj->LastName.'</b></i></div>';
echo '<br>';
echo '<div class="book-qty"> Current Balance<b> '.$obj->Balance.'</b></div>';
echo 'New Balance: <input type="number" name="newBalance" value = "1" min = "1" />';
echo '<br><br>';
echo '<button name="submit_btn" class="save_order">Top Up</button>';
echo '</div>';
echo '</form>';
echo '</div>';
}
}
}
$newBalance="";
if(isset($_POST['submit_btn']) && !empty($_POST['newBalance']) ){
$newBalance = $_POST['newBalance'];
$upsql = "UPDATE users SET Balance = Balance + '$newBalance' WHERE Username='" . $obj->Username . "'";
$stmt = $mysqli->prepare($upsql);
$stmt->execute();
}
?>
</body>
</html>
它抛出了这个通知,因为你需要放在$newBalance = $_POST['newBalance'];里面if(isset($_POST['submit_btn'])){...}并验证它不是空的(或设置).
$newBalance="";
if(isset($_POST['submit_btn']) && !empty($_POST['newBalance']) ){
$newBalance = $_POST['newBalance'];
$upsql = "UPDATE users SET Balance = Balance + '$newBalance'
WHERE Username='" . $obj->Username . "'";
$stmt = $mysqli->prepare($upsql);
$stmt->execute();
}
您也可以使用isset($_POST['newBalance'])而不是!empty($_POST['newBalance'])
旁注:您可能希望为按钮添加提交类型.
echo '<button type="submit" name="submit_btn" class="save_order">Top Up</button>';
然而,它可能不是必需的; 如果您仍然遇到问题,请尝试一下.
编辑:
下
echo '<div class="book-content"><h3>Student Username: '.$obj->Username.'</h3>';
加
echo '<input type="hidden" name="username" value = "'.$obj->Username.'" />';
然后在
$newBalance = $_POST['newBalance'];
加
$username = $_POST['username'];
并将您的查询修改为
$upsql = "UPDATE users SET Balance = Balance + '$newBalance'
WHERE Username='".$username ."'";
我的报价可能有点偏僻
echo '<input type="hidden" name="username" value = "'.$obj->Username.'" />';
您可能需要将其更改为
echo '<input type="hidden" name="username" value = '".$obj->Username."' />';
编辑#2:
由于您已经在使用会话,因此执行此操作的另一种方法<?=$_SESSION['Username'];?>是为其分配变量并将其传递给您的查询.
$username = $_SESSION['Username'];
$upsql = "UPDATE users SET Balance = Balance + '$newBalance'
WHERE Username='".$username ."'";
编辑#3:
你在哪里
if(isset($_POST['search'])){
$searchq = $_POST['search'];
$searchq = preg_replace("#[^0-9a-z]#i","",$searchq);
用它替换它
if(isset($_POST['search'])){
$searchq = $_POST['search'];
$searchq = preg_replace("#[^0-9a-z]#i","",$searchq);
$student = $_POST['search'];
$_SESSION['student'] = $student;
echo $_SESSION['student']; // see what echos here
然后在你的查询中,执行:
$upsql = "UPDATE users SET Balance = Balance + '$newBalance'
WHERE Username='".$student ."'";
基于这种情况:
$_POST['search'] = "student1";
$student = $_POST['search'];
$_SESSION['student'] = $student;
// echo $_SESSION['student'];
$student2 = $student;
echo $student2; // will echo student1