php can't delete more than one row - php

Question

I'm using a form with several checkboxes to make the user to select which rows he want to delete. The code to generate the form is this:
if ($busqueda!=""){
$busca = mysqli_query($con, " SELECT id_user FROM usuarios WHERE
id_user LIKE '%$busqueda%'");
echo "<form action='borrar.php' method='post' enctype='multipart/form-data'>";
while ($array= mysqli_fetch_array($busca)){
$user=makestring($array);
echo"Usuario: <input type='checkbox' name='borrar_usuario' value='$user' />$user<br/>";
}
echo " <input type='submit' name='boton' value='eliminar' />";
echo "</form>";
The code in borrar.php to delete the rows is this:
if(isset($_REQUEST["borrar_usuario"])) {
foreach ($_POST as $valor){
$del_user = $valor;
$q_borrar = "delete from usuarios where id_user in ('$del_user')";
mysqli_query($con, $q_borrar)or die(mysqli_error());
}
//echo "usuario borrado";
header('refresh: 3; url= exito.php');
}
The problem is that only deletes the first row selected and I do not know how to make it to delete all the options selected in the form. Any help, please?

Answer 1

First change the name of your checkbox to include []. Then when you submit the form php will convert it to an array.
<input type='checkbox' name='borrar_usuario[]' value='$user' />
Then in the php code that handles the form submission remove the loop and have this
if(isset($_REQUEST["borrar_usuario"])) {
$q_borrar = "delete from usuarios where id_user in ('" . implode("','", $_POST['borrar_usuario']) . "')";
mysqli_query($con, $q_borrar)or die(mysqli_error());
//echo "usuario borrado";
header('refresh: 3; url= exito.php');
}

Answer 2

I think this will work :
if(isset($_POST['borrar_usuario']))
{
$q_borrar = "delete from usuarios where id_user in ($_POST['borrar_usuario'])";
mysqli_query($con, $q_borrar) or die(mysqli_error());
}