"Unknown column 'geir' in 'field list'" - php

Question

I wrote this query:
$query = "UPDATE encodage_answer
SET Answer = geir
WHERE encodage_question_ID = 128
AND encodage_ID = 305
AND Extra = NULL";
$insert = mysql_query($query, $connection) or die(mysql_error());
But if I run this code I always get the same error:
Unknown column 'geir' in 'field list'
It's probably me but I think I am not saying geir is a column/field; what's the issue?
When I run this query directly in my PHPMyAdmin it works great.
Update: Full code:
The answer exists, $Extra variable is Null
$AnswerExists = answer_exists($Question_ID, $encodage_ID, $Extra);
if($AnswerExists <> ""){
if($Answer != NULL){
$correctAnswer = mysql_prep($Answer);
if($Extra != NULL){
$query = "UPDATE `encodage_answer` SET `Answer` = '" . mysql_prep($Answer) . "' WHERE `ID` = '" . $AnswerExists . "'";
$insert = mysql_query($query, $connection) or die(mysql_error());
$query2 = "UPDATE `encodage_answer` SET `Extra` = '" . $Extra . "' WHERE `ID` = '" . $AnswerExists . "'";
$insert = mysql_query($query2, $connection) or die(mysql_error());
}else{
$querytest = "UPDATE `encodage_answer` SET Answer = " . $Answer . " WHERE ID = " . $AnswerExists;
$insert = mysql_query($querytest, $connection) or die(mysql_error());
}
}
}
function answer_exists($Question_ID, $encodage_ID, $Extra){
global $connection;
$trfa = false;
echo $Question_ID . " - " . $encodage_ID . "<br />";
if($Extra <> ""){
$query = "SELECT *
FROM encodage_answer
WHERE encodage_ID = {$encodage_ID} AND encodage_question_ID = {$Question_ID} AND Extra = {$Extra}";
}else{
$query = "SELECT *
FROM encodage_answer
WHERE encodage_ID = {$encodage_ID} AND encodage_question_ID = {$Question_ID}";
}

Answer 1

Try putting single quotes around geir. By not quoting the string you want to set the column to, the SQL backend thinks you want to set the value of the Answer column to the value of the geir column. Since the geir column doesn't exist in your table, it throws an error.
Edit: I suspect that PHPMyAdmin has some kind of SQL statement filtering to catch cases like this, and automatically puts quotes around the string for you.

Answer 2

Thanks for the help to everyone! I'm changing all queries to a safer format! SQL-Injection treats are no longer an issue! Thanks for the tip!
Concerning my question:
I'am a complete idiot! After searching for a solution for 20 hours I found my error! The error was for another query. I'm very sorry for wasting your time but I'm a newbie (ergo, the sql-injection issue), so I hope I am allowed to make a few mistakes.
Thanks
Jens