所以,我试图减去2个变量,$ price到$ user_balance(当插入帖子时,我想要(新)$ user_balance =(当前)$ user_balance - $ price,但它没有减去,怎么可以修复(这个代码)不起作用的是exit();)
例:
(余额在用户表中)
(帖子转到帖子表)
在将帖子引入数据库之前的平衡:100
产品价格在数据库中介绍:50
在数据库中引入产品价格后的余额应该是100-50,所以50
function insertPost(){
if(isset($_POST['sub'])){
global $con;
global $user_id;
$content = htmlentities($_POST['content']);
$content2 = htmlentities($_POST['content2']);
$price = htmlentities($_POST['price']);
$pclass = htmlentities($_POST['pclass']);
$specificclass = htmlentities($_POST['specificclass']);
$upload_image = $_FILES['upload_image']['name'];
$image_tmp = $_FILES['upload_image']['tmp_name'];
$random_number = rand(1, 100);
$user_balance = $row_posts['user_balance'];
if(strlen($content) > 250){
echo "<script>alert('Utiliza menos de 250 carácteres)</script>";
echo "<script>window.open('home.php', '_self')</script>";
}else{
move_uploaded_file($image_tmp, "imagepost/$upload_image.$random_number");
$insert = "insert into posts (user_id, post_content, post_content2, post_price, post_class, post_specificclass, upload_image, post_date) values('$user_id', '$content', '$content2', '$price', '$pclass', '$specificclass', '$upload_image.$random_number', NOW())";
$run = mysqli_query($con, $insert);
$user_balance = $user_balance - $price;
if($run){
echo "<script>window.open('home.php', '_self')</script>";
$update = "update users set posts='yes' where user_id='$user_id'";
$update = "update users set user_balance='$user_balance - $price' where user_id='$user_id'";
$run_update = mysqli_query($con, $update);
}
exit();
}
}
}
看来你做两次减法
更改
$update = "update users set user_balance=$user_balance - $price where user_id='$user_id'";
至
$update = "update users set user_balance = user_balance - $price WHERE user_id='$user_id'";
或保持你的变量
$user_balance = $user_balance - $price;
$update = "UPDATE users SET user_balance = '$user_balance' WHERE user_id='$user_id'";
如果您选择第一个解决方案,请删除
$user_balance = $user_balance - $price;
您之前的查询也被覆盖,不会被执行
这个
$update = "update users set posts='yes' where user_id='$user_id'";