Question

I’m trying to figure out how I can insert a NULL value into a column of newly inserted row.

I’m working on “post icons” which will display a small icon for the thread on the thread list. The icons use RADIO buttons in the form. By default it is set to No Icon. I was wondering what to do for the value of that radio button to make it null? I tried setting value as NULL but it just inserts the word “NULL” into the database.

            $thread_sql = "
            INSERT INTO forum_threads (
                user_id,
                forum_id,
                thread_postdate,
                thread_lastpost,
                thread_title,
                thread_description,
                thread_icon
            ) VALUES (
                '$_SESSION[user_id]',
                '$_GET[f]',
                '$date',
                '$date',
                '$_POST[topictitle]',
                '$_POST[topicdescription]',
                '$_POST[posticon]'
            )
        ";
        $thread_query = @mysqli_query ($db_connect, $thread_sql);

Answer 1

Just do something like this (PDO):

$stmt  = $db->prepare('INSERT INTO foo(bar) values (?);');
$stmt->execute(array($value=='NULL'? NULL,$value));

Or with mysql:

mysql_query('INSERT INTO foo(bar) 
   values ('.($value=='NULL'? 'NULL',"'".mysql_real_escape_string($value)."'").')';