[SOLVED] Make blank form fields always send NULL to MySQL

[pakenney38]

Say I've got a form variable set to a new variable like so:

$newvar = $_POST['newvar'];

If the newvar form field contained no value, is there any way to prevent PHP from sending $newvar as '' in a MYSQL statement and instead send a NULL value for $newvar?

[fenway]

It depends on your INSERT statement... if you're blindly quoting this value, you're stuck.  You'd need to check in in-line... could you post just the relevant code snippet (NOT the whole file)?

[Cagecrawler]

<?php $newvar = ($_POST['newvar'] == '')? NULL : $_POST['newvar']; ?>

[fenway]

Actually, you'd still need to quote the non-NULL value, so that's not it.

[pakenney38]

Well ideally, I would like to just do something like

$query = "INSERT INTO table (blah1, blah2, blah3, newvar) VALUES ($blah1, $blah2, $blah3, $newvar)";
mysql_query($query);

But if the form field associated with $newvar was not filled in, I would like it to not submit a value to MySQL. If there is some easy way of doing this without going through the whole

if ($newvar != '')

before I run my query, then I would like to know how to do that. I suppose I could just use $_POST['newvar'] in my MySQL query, but in my situation, I can't always do it that way.

[pakenney38]

<?php $newvar = ($_POST['newvar'] == '')? NULL : $_POST['newvar']; ?>

Wow that is interesting, but what does it mean?

[pakenney38]

I guess this is some sort of case check kinda like

 

if ($_POST['newvar'] == '')
{$newvar == NULL;}
else
{$newvar == $_POST['newvar'];}

[fenway]

This should work:

$query = "INSERT INTO table (blah1, blah2, blah3, newvar) VALUES ($blah1, $blah2, $blah3, ( $_POST['newvar'] == '' ? NULL : $newvar) )";

 

But why aren't you quoting your strings?

[pakenney38]

Oh I just quickly wrote that as an example. Sorry. It's quoted in the actual project.

[pakenney38]

This is obviously my first exposure to the ternary operator in PHP, but I love it.

What I needed was something like this:

$newvar = (empty($_POST['newvar'])) ? NULL : $_POST['newvar'];

Just knowing that the ternary operator exists is going to make my life so much easier.