Is it possible to have a HTML SELECT/OPTION value as NULL using PHP?

Question

The following is a snippet from my HTML form which pulls the options from the table rows accordingly.

What I want to do is have the first option value to be NULL so

Answer 1

Yes, it is possible. You have to do something like this:

if(isset($_POST['submit']))
{
  $type_id = ($_POST['type_id'] == '' ? "null" : "'".$_POST['type_id']."'");
  $sql = "INSERT INTO `table` (`type_id`) VALUES (".$type_id.")";
}

It checks if the $_POST['type_id'] variable has an empty value. If yes, it assign NULL as a string to it. If not, it assign the value with ' to it for the SQL notation

Answer 2

In php 7 you can do:

$_POST['value'] ?? null;

If value is equal to '' as said in other answers it will also send you null.

Answer 3

that's why Idon't like NULL values in the database at all.
I hope you are having it for a reason.

if ($_POST['location_id'] === '') {
  $location_id = 'NULL';
} else {
  $location_id = "'".$_POST['location_id']."'";
}
$notes = mysql_real_escape_string($_POST['notes']);
$ipid  = mysql_real_escape_string($_POST['ipid']);

$sql="UPDATE addresses 
    SET notes='$notes', location_id=$location_id
    WHERE ipid = '$ipid'";

echo $sql; //to see different queries this code produces
// and difference between NULL and 'NULL' in the query

Answer 4

No, POST/GET values are never null. The best they can be is an empty string, which you can convert to null/'NULL'.

if ($_POST['value'] === '') {
    $_POST['value'] = null; // or 'NULL' for SQL
}

Answer 5

All you need is a check on the post side of things.

if(empty($_REQUEST['type_id']) && $_REQUEST['type_id'] != 0)
    $_REQUEST['type_id'] = null;