delete multiple row in php table data using cheque box

I have this script where the delete function is not working. The row gets removed from the table as the same was called for.. but the same re-appears as the same is not been removed from the actual database..

My table's :

This is given for the delete button:

<th >Follow Up Date</th>
<th >Name SM</th>
<th >Entered Date</th>
<th >Edit</ht>
<th ><button type="button" name="delete_all" id="delete_all" class="btn btn-danger btn-xs">Delete</button></th>

The second where the there is check box:

<td><?php echo $row["NameSM"]; ?></td>
<td><?php echo $row["EnteredDate"]; ?></td>
<td><input type="button" name="edit" value="Edit" id="<?php echo $row["id"]; ?>" class="btn btn-info btn-xs edit_data" /></td>
<td><input type="checkbox" class="delete_checkbox" value="'.$row["id"].'" /></td>

The Delete Script :

<style>
.removeRow
{
    background-color: #FF0000;
    color:#FFFFFF;
}
</style>
<script>
$(document).ready(function(){

    $('.delete_checkbox').click(function(){
        if($(this).is(':checked'))
        {
            $(this).closest('tr').addClass('removeRow');
        }
        else
        {
            $(this).closest('tr').removeClass('removeRow');
        }
    });

    $('#delete_all').click(function(){
        var checkbox = $('.delete_checkbox:checked');
        if(checkbox.length > 0)
        {
            var checkbox_value = [];
            $(checkbox).each(function(){
                checkbox_value.push($(this).val());
            });

            $.ajax({
                url:"delete.php",
                method:"POST",
                data:{checkbox_value:checkbox_value},
                success:function()
                {
                    $('.removeRow').fadeOut(1500);
                }
            });
        }
        else
        {
            alert("Select atleast one records");
        }
    });

});
</script>

The delete.php page :

<?php

//database_connection.php = $connect = new PDO("mysql:host=localhost;dbname=u771775069_data", "root", "");
include('database_connection.php');

if(isset($_POST["checkbox_value"]))
{
 for($count = 0; $count < count($_POST["checkbox_value"]); $count++)
 {
  $query = "DELETE FROM data WHERE id = '".$_POST['checkbox_value'][$count]."'";
  $statement = $connect->prepare($query);
  $statement->execute();
 }
}

?>