How can hidden fields in a form be used to compare values in a MySQL table using PHP?

Hidden fields in a form can be used to store values from a MySQL table and pass them to PHP for comparison. This can be useful when you want to compare user input with values stored in a database without revealing those values to the user. By setting the hidden field value to the desired value from the database, you can then retrieve and compare it in your PHP code to validate user input. 

<form method="post" action="compare.php">
    <input type="hidden" name="hidden_value" value="<?php echo $row['value_from_database']; ?>">
    <input type="text" name="user_input">
    <input type="submit" value="Submit">
</form>
```

In your PHP script (compare.php), you can retrieve the hidden field value and compare it with the user input:

```php
$hidden_value = $_POST['hidden_value'];
$user_input = $_POST['user_input'];

if($hidden_value == $user_input) {
    echo "Values match!";
} else {
    echo "Values do not match!";
}

Keywords

hidden fields form MySQL table PHP comparison

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