PHP mysql 双向排序

Question

I am making a website that only shows a table from a mysql database and have like 10 colums i want to be able to sort. Like both up and down or how i should say it. I have a code allready ass you can see, but it only works 1 way is it possible to make and easy sorting 2 ways? if so could someone help me with it?

I am very new to PHP

Thanks for all the answers.

    $sql = "SELECT * FROM server1";
if(!isset($_GET['sort'])) {

}
elseif ($_GET['sort'] == 'id')
{
    $sql    .= " ORDER BY ID";
}
elseif ($_GET['sort'] == 'vsite')
{
    $sql .= " ORDER BY vsite";
}
elseif ($_GET['sort'] == 'registrar')
{
    $sql .= " ORDER BY registrar";
}
elseif ($_GET['sort'] == 'eier')
{
    $sql .= " ORDER BY eier";
}
elseif ($_GET['sort'] == 'ns')
{
    $sql .= " ORDER BY ns";
}
elseif ($_GET['sort'] == 'a')
{
    $sql .= " ORDER BY a";
}
elseif ($_GET['sort'] == 'mx')
{
    $sql .= " ORDER BY mx";
}
elseif ($_GET['sort'] == 'flyttet')
{
    $sql .= " ORDER BY flyttet";
}
elseif ($_GET['sort'] == 'slettet')
{
    $sql .= " ORDER BY slettet";
}
elseif ($_GET['sort'] == 'delt')
{
    $sql .= " ORDER BY delt";
}
elseif ($_GET['sort'] == 'behkd')
{
    $sql .= " ORDER BY behkd";
}
elseif ($_GET['sort'] == 'varenr')
{
    $sql .= " ORDER BY varenr";
}
elseif ($_GET['sort'] == 'server')
{
    $sql .= " ORDER BY server";
}
elseif ($_GET['sort'] == 'sist')
{
    $sql .= " ORDER BY sistoppdatert";
}

Answer 1

嗯只需在这样的查询后添加 ASC 或 DESC

$sql .= " ORDER BY server DESC";

Answer 2

Such a long code were not needed to be able to sort the tables, so i worte something like this:

<?php
if(!isset($_GET['field'])) $field = 'ID'; else $field = $_GET['field'];
if(!isset($_GET['sorting'])) $sort = 'ASC'; else $sort = $_GET['sorting'];


$sql = "SELECT * FROM server1 ORDER BY " .$field." ".$sort;

if($sort == 'ASC') $sort = 'DESC'; else $sort = 'ASC';
?>