edlucas
-
Posts
2 -
Joined
-
Last visited
Posts posted by edlucas
-
-
Add validations to the transfers script to prevent a negative transfer or the selection of the same account for both the “to” and “from.”
I have honestly no idea on how to do this:
// if statements right here
if ($amount > 0) {
if ($to != $from) {
// logic to add the balance to the account
} else {
<p>To and From cannot be the same
}
} else {
<p>Please deposit an amount greater than zero.
}
}
//logic to add the balance to the accountThis is all I have for adding it, but I dont know what else to do and it gives me an error when I do 0. Help please!
Chapter 11
in PHP and MySQL for Dynamic Web Sites: Visual QuickPro Guide (5th Edition)
Posted
Yeah I saw my problem a few to extra brackets this is how the code I have now looks.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Transfer Funds</title>
</head>
<body>
<h1>Transfer Funds</h1>
<?php # Script 11.7 - transfer.php
// This page performs a transfer of funds from one account to another.
// This page uses transactions.
// Always need the database connection:
$dbc = mysqli_connect('edelucas.colutah.org', 'edelucas_user', 'Deluck11d', 'edelucas_banking') OR die('Could not connect to MySQL: ' . mysqli_connect_error() );
// Check if the form has been submitted:
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
// Minimal form validation:
if (isset($_POST['from'], $_POST['to'], $_POST['amount']) &&
is_numeric($_POST['from']) && is_numeric($_POST['to']) && is_numeric($_POST['amount']) ) {
// if statements right here
$from = $_POST['from'];
$to = $_POST['to'];
$amount = $_POST['amount'];
if ($amount > 0) {
echo $amount;
$good = 'yes';
if ($to != $from) {
// logic to add the balance to the account
} else {
echo '<p>To and From cannot be the same</p>';
$good = 'no';
}
} else {
echo '<p>Please deposit an amount greater than zero.</p>';
$good= 'no';
}
if ($good == 'yes') {
echo '<p>The transfer was a success!</p>';
}
//logic to add the balance to the account
// Make sure enough funds are available:
$q = "SELECT balance FROM accounts WHERE account_id=$from";
$r = @mysqli_query($dbc, $q);
$row = mysqli_fetch_array($r, MYSQLI_ASSOC);
if ($amount > $row['balance']) {
echo '<p class="error">Insufficient funds to complete the transfer.</p>';
} else {
// Turn autocommit off:
mysqli_autocommit($dbc, FALSE);
$q = "UPDATE accounts SET balance=balance-$amount WHERE account_id=$from";
$r = @mysqli_query($dbc, $q);
if (mysqli_affected_rows($dbc) == 1) { // If it ran OK.
$q = "UPDATE accounts SET balance=balance+$amount WHERE account_id=$to";
$r = @mysqli_query($dbc, $q);
if (mysqli_affected_rows($dbc) == 1) { // If it ran OK.
mysqli_commit($dbc);
} else {
mysqli_rollback($dbc);
echo '<p>The transfer could not be made due to a system error. We apologize for any inconvenience.</p>'; // Public message.
echo '<p>' . mysqli_error($dbc) . '<br>Query: ' . $q . '</p>'; // Debugging message.
}
} else {
mysqli_rollback($dbc);
echo '<p>The transfer could not be made due to a system error. We apologize for any inconvenience.</p>'; // Public message.
echo '<p>' . mysqli_error($dbc) . '<br>Query: ' . $q . '</p>'; // Debugging message.
}
}
}else { // Invalid submitted values.
echo '<p class="error">Please select a valid "from" and "to" account and enter a numeric amount to transfer.</p>';
}
} // End of submit conditional.
// Always show the form...
// Get all the accounts and balances as OPTIONs for the SELECT menus:
$q = "SELECT account_id, CONCAT(last_name, ', ', first_name) AS name, type, balance FROM accounts LEFT JOIN customers USING (customer_id) ORDER BY name";
$r = @mysqli_query($dbc, $q);
$options = '';
while ($row = mysqli_fetch_array($r, MYSQLI_ASSOC)) {
$options .= "<option value=\"{$row['account_id']}\">{$row['name']} ({$row['type']}) \${$row['balance']}</option>\n";
}
// Create the form:
echo '<form action="transfer.php" method="post">
<p>From Account: <select name="from">' . $options . '</select></p>
<p>To Account: <select name="to">' . $options . '</select></p>
<p>Amount: <input type="number" name="amount" step="0.01" min="1"></p>
<p><input type="submit" name="submit" value="Submit"></p>
</form>';
mysqli_close($dbc);
?>
</body>
</html>