Question

我有一个需要修理的个人项目。下面的代码应该从工人帐户中提取一笔金额（借记帐户），但它会返回一个空格并显示错误。请根据具体情况我需要错误或错过步骤的帮助。我是php的新手这是我的代码

// connect db   
<?php
$username="root";
$server="localhost";
$dbname="workers_db";
$password="worded";
    $conn=mysql_connect($server,$username,$password);
    mysql_select_db($dbname) or die ("SERVER ERROR".mysql_error());
?>

// check
<?php
if(isset($_GET['withdraw']))
{

$Req="SELECT * FROM balance";
$query=mysql_query($Req);
$nums=mysql_fetch_assoc($query);
//echo $nums['CurrentB'];
$amount=$_GET['amount'];
$newB= ceil($nums['CurrentB']- $amount);
///////////////
if($newB>5000)
{

$amount=$_GET['amount'];
$withdrawal="UPDATE balance SET CurrentB=$newB,LastWithdraw=$amount,date=now() WHERE b_id=1; ";
$query2=mysql_query($withdrawal);
//$nums=mysql_fetch_assoc($query2);
    if($query2)
    {
    $Req="SELECT * FROM balance";
    $query=mysql_query($Req);
    $nums=mysql_fetch_assoc($query);
    echo "Your new current account balance is". '  '.$nums['CurrentB'];
    echo "<br/>Your Last Withdrawal was ". '  '.$nums['LastWithdraw'];
    echo "<br/>Your Last Withdrawal Date was  on". '  '.$nums['date'];
    }
}
else
{
echo 'INSUFFICIENT BALANCE TO CONTINUE THIS TRANSACTION';
}
///////////////
}
else
{
$Req="SELECT * FROM balance";
$query=mysql_query($Req);
$nums=mysql_fetch_assoc($query);
echo "Your current account balance is". '  '.$nums['CurrentB'];
}
?>

<?php
if(!isset($_GET['withdraw']))
{
?>
//the form
<form action="<?php  $_SERVER['PHP_SELF']; ?>" method="GET" enctype="multipart/form-data">
Amount to Withdraw: &emsp;<input type="text" name="amount">
<input type="Submit" name="withdraw" value="Proceed">
</form>
<?php
}
?>
//end
<br/><a href="index.php">EXIT</a>

Answer 1

编辑，对您的代码进行了一些更改，添加了内联注释，希望有所帮助

<?php

$username="root";
$server="localhost";
$dbname="workers_db";
$password="worded";
$conn=mysql_connect($server,$username,$password);
mysql_select_db($dbname) or die ("SERVER ERROR".mysql_error());


if(isset($_GET['withdraw'])) {

    $Req="SELECT * FROM balance"; // maybe you should you add a WHERE clause here
    $query=mysql_query($Req);
    $nums=mysql_fetch_assoc($query);

    // what is the initial balance for this user? uncomment the line below and check the the numbers
    // echo $nums['CurrentB'];

    $amount=$_GET['amount'];
    $currentBalance = $nums['CurrentB'];
    $newBalance = ceil($currentBalance - $amount);

    // what is the newBalance for this user? uncomment the line below and see
    // print $newBalance;

    // if the balance after withdrawal is more the 5000 proceed
    if($newBalance > 5000) {
        $amount=$_GET['amount'];
        $withdrawal="UPDATE balance SET CurrentB=$newB,LastWithdraw=$amount,date=now() WHERE b_id=1; ";
        $query2=mysql_query($withdrawal);
        //$nums=mysql_fetch_assoc($query2);
        if($query2) {
        $Req="SELECT * FROM balance";
            $query=mysql_query($Req);
            $nums=mysql_fetch_assoc($query);
            echo "Your new current account balance is". '  '.$nums['CurrentB'];
            echo "<br/>Your Last Withdrawal was ". '  '.$nums['LastWithdraw'];
            echo "<br/>Your Last Withdrawal Date was  on". '  '.$nums['date'];
        }
    }
    // else give out error message
    else {
        echo 'INSUFFICIENT BALANCE TO CONTINUE THIS TRANSACTION';
    }

}
else {

    $Req="SELECT * FROM balance"; // maybe you should add here a WHERE clause, ex. WHERE b_id=xx
    $query=mysql_query($Req);
    $nums=mysql_fetch_assoc($query);
    echo "Your current account balance is". '  '.$nums['CurrentB'];

    echo '<form action="'.$_SERVER['PHP_SELF'] .'" method="GET" enctype="multipart/form-data">
    Amount to Withdraw: &emsp;<input type="text" name="amount">
    <input type="Submit" name="withdraw" value="Proceed">
    </form>';
    echo '<br/><a href="index.php">EXIT</a>';
}
?>

如果您想检查可用余额以进行提款，测试当前余额是否严格小于要提取的金额，如果是，则触发错误消息。

如果当前余额更大或相等，意味着剩余余额为零，则可以处理提款。

if ($nums['CurrentB']<$amount) echo "not enough money";
else {
    // process the withdrawal
}

您正在进行的测试是检查剩余余额是否大于5000，如果为真，则处理余额，如果为假则给出错误。

您当然可以包含此强制性剩余余额，但在测试中，您需要检查初始余额是否远高于5000最低值。例如：

if ($nums['CurrentB'] - $amount < 5000 ) echo "limit exceeded";
else {
    // process the withdrawal
}

请确保您在初始余额和余额之间做出区别。

php提款代码无法正常工作

1 个答案: