Set value to NULL in MySQL

Question

I want a value to be set to NULL if nothing is put into the text box in the form I\'m submitting. How can I make this happen? I\'ve tried inserting \'NULL

Answer 1

if (($_POST['nullfield'] == 'NULL') || ($_POST['nullfield'] == '')) {
   $val = 'NULL';
} else {
   $val = "'" . mysql_real_escape_string($_POST['nullfield']) . "'";
}

$sql = "INSERT INTO .... VALUES ($val)";

if you put 'NULL' into your query, then you're just inserting a 4-character string. Without the quotes, NULL is the actual null value.