Unable to Submit to Database - php

Question

Using the MVC Framework, I have made some code that is meant to add information to the Database.
In Index.php (views)
<form method="post" action="<?php echo URL;?>note/updatetopic">
<select>
<option value="1">Coasts</option>
<option value="2">Energy Demand</option>
</select>
<input type="submit" name="topic_selection" value="Choose" />
</form>
The Code above is meant to post information about what a user would like to revise.
In note.php (controllers)
public function updatetopic() {
if (isset($_POST['topic_selection'])) {
$note_model = $this->loadModel('Note');
$note_model->updatetopic($_POST['topic_selection']);
}
header('location: ' . URL . 'note');
}
The Code above is meant to get information from the code in index.php and forward it onto the note_model where it runs a function.
In note_model.php (models)
public function updatetopic($topic_selection)
{
$topic_selection = strip_tags($topic_selection);
$sql = "INSERT INTO users (topic_revising) VALUES (:topicselected) WHERE user_id=:user_id";
$query = $this->db->prepare($sql);
$query->execute(array(':topicselected' => $topic_selection, ':user_id' => $_SESSION['user_id']));
$count = $query->rowCount();
if ($count == 1) {
return true;
} else {
$_SESSION["feedback_negative"][] = TOPIC_UPDATE_FAILED;
}
// default return
return false;
}
This is meant to validate the submitted information and insert it into the database but it outputs:
$_SESSION["feedback_negative"][] = TOPIC_UPDATE_FAILED;
Can someone please help me and tell me what im doing wrong? Thanks.

Answer 1

You are not choosing any name for your select tag:
try like this:
<select name="topic">
<option value="1">Coasts</option>
<option value="2">Energy Demand</option>
</select>
And now get the the value of yuor drop down list:
if (isset($_POST['topic'])) {
$note_model = $this->loadModel('Note');
$note_model->updatetopic($_POST['topic']);
// $_POST['topic'] == 1 or 2 depends upon selection
}
you can change it like:
<select name="topic">
<option value="coasts">Coasts</option>
<option value="Energy_Demand">Energy Demand</option>
</select>
now u'll get the real value of selected list item and can move further....

Answer 2

Your SQL query will not work as you have tagged mysql which does not support this kind of syntax:
INSERT INTO users (topic_revising) VALUES (:topicselected) WHERE user_id=:user_id
Basically there is no WHERE in MySQL (MySQL Insert Where query)
You should check for duplicated either in select query, or if there are unique keys - use ON DUPLICATE KEY. Also take a look at the linked topic