Unknown Column in 'field list' php mysql

Unknown Column in 'field list' php mysql

I've looked everywhere but I cant find an answer for this question. I've
seen several solutions that have helped people, but when I try it, I see
I'm doing everything right and have nothing to fix. I'm making a forum and
i'm trying to insert these into a mysql table but every time I try it
says:
Unknown column '6c09e4fe82d47011bf9b25b05946307f' in 'field list'.
The long code is a user id for one of the users, and Its supposed to get
inserted, but for some reason its looking for a column with that name.
I've only gotten up to the first query with an error so the second part
might be totally fine, I don't know.
$sql = "INSERT INTO
topics(topic_subject,
topic_date,
topic_cat,
topic_by)
VALUES('" .
mysql_real_escape_string($_POST['topic_subject']) . "',
NOW(),
" .
mysql_real_escape_string($_POST['topic_cat']) .
",
". $_SESSION['userid'] ."
)";
$result = mysql_query($sql);
if(!$result)
{
//something went wrong, display the error
echo 'You did everything right, yet there is an error. WEIRD
RIGHT???<br /><br />' . mysql_error();
$sql = "ROLLBACK;";
$result = mysql_query($sql);
}
else
{
//the first query worked, now start the second, posts query
//retrieve the id of the freshly created topic for usage in
the posts query
$topicid = mysql_insert_id();
$sql = "INSERT INTO
posts(post_content,
post_date,
post_topic,
post_by)
VALUES
('" .
mysql_real_escape_string($_POST['post_content']) .
"',
NOW(),
" . $topicid . ",
". $_SESSION['userid'] ."
)";
$result = mysql_query($sql);