SQL error: Unknown column in 'where clause' I have following very simple PHP MySQL Query:

$sql = 'SELECT * FROM bundesland WHERE bkuerzel = ' . $_GET['q'];
$result = mysql_query($sql, $con);


When I execute the query with a click on a item with the value "Wien" on a dropdown menu I get "SQL error:Unknown column 'Wien' in 'where clause' in", but as you can see in the picture below I have the column.
The value for $_GET['q'], which must be Wien, should be in quotes

$sql = "SELECT * FROM bundesland WHERE bkuerzel = '" . $_GET['q'] . "'";
$result = mysql_query($sql, $con);


Without putting quotes around $_GET['q'], mysqld thinks the value of $_GET['q'] is a field.