Php 有人能告诉我为什么这一行被两次插入我的数据库吗?
当我单击“创建”按钮时,我希望将记录添加到我的类别表中,但是由于某些原因,它被添加了两次-即使我只单击了一次按钮。你知道为什么吗?我看不到还有什么别的地方Php 有人能告诉我为什么这一行被两次插入我的数据库吗?,php,mysql,Php,Mysql,当我单击“创建”按钮时,我希望将记录添加到我的类别表中,但是由于某些原因,它被添加了两次-即使我只单击了一次按钮。你知道为什么吗?我看不到还有什么别的地方 if(isset($\u POST['create']){可以从中调用。我整个项目中只有4页 <?php require('dbConnect.php'); //use the variables we created in volleyLogin.php session_start(); $
if(isset($\u POST['create']){
可以从中调用。我整个项目中只有4页
<?php require('dbConnect.php');
//use the variables we created in volleyLogin.php
session_start();
$username = $_SESSION['username'];
$user_id = $_SESSION['user_id'];
echo "user name is " . $username . "<br>";
echo "user id is " . $user_id . "<br>";
if (isset($_POST['create'])) {
$category = ($_POST['category']);
$name = ($_POST['name']);
$phonenumber = ($_POST['phonenumber']);
$address = ($_POST['address']);
$comment = ($_POST['comment']);
//check if the category being entered is already there
$check="SELECT COUNT(*) FROM category WHERE cat_name = '$_POST[category]'";
$get_value = mysqli_query($con,$check);
//check the number of values of the category being posted
$data = mysqli_fetch_array($get_value, MYSQLI_NUM);
//if the category name already exists in the category table
if($data[0] >= 1) {
echo "This Already Exists<br/>";
}
else if ($data[0] < 1)
{
//if it's not in there, then add the category in the category table.
$sql = "INSERT INTO category VALUES(NULL, '{$category}', '$user_id')";
$rs1=mysqli_query($con, $sql);
if ($con->query($sql) === TRUE) {
echo "Yes, it's been added correctly";
} else {
echo "Error: " . $sql . "<br>" . $con->error;
}
}
$con->close();
}
?>
<!doctype html>
<html>
<body>
<h2>Create new Contact</h2>
<form method="post" action="" name="frmAdd">
<p><input type="text" name = "category" id = "category" placeholder = "category"></p>
<p><input type="text" name = "name" id = "name" placeholder = "name"></p>
<p><input type="text" name = "phonenumber" id = "phonenumber" placeholder = "phone number"></p>
<p><input type="text" name = "address" id = "address" placeholder = "address"></p>
<p><input type="text" name = "comment" id = "comment" placeholder = "comment"></p>
<p><input type="submit" name = "create" id = "create" value = "Create new Contact"></p>
<a href="exit.php">Exit</a>
</form>
</body>
</html>
您使用两种不同的方法运行了$sql
查询两次:
$rs1=mysqli_query($con, $sql);
if ($con->query($sql) === TRUE) {
这就是为什么你会得到重复的条目
您应该删除$rs1
,因为它没有被使用,或者在条件上验证它的值,而不是再次运行该函数。谢谢。我不明白为什么它可以工作,但它确实可以。我现在会在新书《PHP for the Web》中阅读这些部分。显然,我会在9分钟内接受您的答案。没关系。您可能会喜欢只是混淆了两种不同的东西。当你这样做时,请检查:。你的代码非常容易受到攻击。永远不要将输入数据直接放入查询中。永远不要相信它们,它们可能会被黑客攻击。使用mysqli\u real\u escape\u string
或使用准备好的语句。