What are the potential issues with using "echo mysql" to display column headers in PHP?

Using "echo mysql" to display column headers in PHP is incorrect because it mixes PHP and MySQL syntax. Instead, you should fetch the column headers from the MySQL result set and then display them using PHP. This can be achieved by using the mysqli_fetch_field_direct() function to retrieve the column names.

// Assuming $result is the MySQL result set
while ($field = mysqli_fetch_field_direct($result)) {
    echo $field->name . "<br>";
}