INSERT完成后，为什么DELETE命令不起作用？

Question

我从table1将该数据提取到表单输入值中，并尝试将其插入到table2中。然后，我希望将其从表1中删除。但是，在完成INSERT之后，DELETE不起作用。没有IF，有什么方法可以做到这一点吗？怎么样？ 看到我试过了：

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "lock_access";

$conn = mysqli_connect($servername, $username, $password);

if(!$conn)
{ echo 'Not connected'; 
}
if(!mysqli_select_db($conn,$dbname))
{
    echo 'DB Not selected'; }

$fn = $_POST['full_name'];
$fln = $_POST['flatno'];
$gn = $_POST['gender'];
$pcn = $_POST['pcardno'];

$sql = "INSERT INTO approved (full_name, flat_number, gender, new_card) VALUES('$fn', '$fln', '$gn', '$pcn')";


if(mysqli_query($conn, $sql))
{

     DELETE FROM lock_access WHERE full_name='$fn';
}

else {
     echo "Application not received. ";
}

?>