I have this <input type="text" name="Fax" id="faxbox" maxlength="9" value="<?php echo $row['Fax'] ?>" />
I want to leave it blank on submit. On Data Base, that column (as int) is set to allow nulls too.
But when i submit, my empty/blank field is turn to 0 (zero) by MySql. I want that appear NULL instead 0.
What should I do? I try if(empty($_POST['Fax'])){$Fax=NULL;} but wont work.
You need to actually use a string null, e.g.
$Fax = 'NULL';
A php null will be converted into an empty string if you use it in a string context anywhere.
followup:
if you have:
$Fax = null;
$sql = "INSERT INTO .... VALUES ($Fax)";
you end up with
INSERT INTO ... VALUES ()
because the PHP null was converted to an empty string. But if you have
$Fax = 'null'; // a string whose contents is the word 'null'
then the query statement will actually be
INSERT INTO ... VALUES (null)
because the value of the string was the word null, which then will be treated as an sql null.
In order to insert NULL value in MySQL using php, you need to do it like this:
INSERT INTO table (field,field2) VALUES (NULL,3)
in your case, try this:
$Fax = !empty($Fax) ? "'$Fax'" : "NULL";
INSERT INTO tableName (Fax) VALUES ($Fax);
