Why is it inserting 0's instead of blank spaces into my DB using php?

Question

I have an insert:

$sql = 'INSERT into orders SET 
fax_int_prefix = "'.$_SESSION['fax_int_prefix'].'", 
fax_prefix = "'.$_SESSION['fax_prefix'].'", 
fax_first = "'.$_SESSION['fax_first'].'", 
fax_last = "'.$_SESSION['fax_last'];

The value of all of these fields is that they are blank right before the insert. Here is an example of one of them I echo'd out just before the insert:

$_SESSION[fax_prefix] =

For some reason it inserts the integer 0, instead of a blank value or null, as it should. Why is it inserting 0's instead of blank spaces into my DB?

Answer 1

Check the structure of your table. It's possible that it is not of type char or varchar (or that it is and has a default value set to '0'). To do this you can use phpmyadmin, SQLyog or other MySql admin programs.

Edit: If you want to store integers, but have the option of no value then make sure the type is nullable. i.e.: column_name INT(n) DEFAULT NULL

Answer 2

Check the schema of your database. Most likely they are integer fields or such.

SHOW FIELDS FROM orders;

or

SHOW CREATE TABLE orders;

might help. Additionally just printing out a variable is no good check, rather use var_dump().