Undefined Offset: 0 - Codeigniter - php

Question

When I send a Request to this Page including POST-DATA ({"bot_hw_id":"2147483647"}), i get the following error:
<p>Severity: Notice</p>
<p>Message: Undefined offset: 0</p>
<p>Filename: models/prometheus_model.php</p>
<p>Line Number: 26</p>
My Code:
Controller(update_bot function):
[code]public function update_bot()
{
$bot_data = json_decode($this->input->post('bot_data'));
$to_update = array(
'bot_last_update' => time(),
'bot_ip' => $_SERVER['REMOTE_ADDR'],
'bot_port' => $_SERVER['REMOTE_PORT']
);
$bot_data = $this->prometheus_model->get_bot_data_by_hw_id(/*$bot_data->{'bot_hw_id'}*/$bot_data->{'bot_hw_id'});
//echo $bot_data['bot_id'];
print_r($bot_data);
$this->prometheus_model->update('bots', array('bot_id' => $bot_data['bot_id']), $to_update);
//var_dump($bot_data);
}
Model(prometheus_model):
<?php
class Prometheus_model extends CI_Model {
var $tables = array(
'bots' => 'bots'
);
function __construct() {
parent::__construct();
}
public function tablename($table = NULL) {
if(! isset($table)) return FALSE;
return $this->tables[$table];
}
public function get($table, $where = array(), $single = FALSE, $order = NULL) {
$this->db->where($where);
if(isset($order)) {
$this->db->order_by($order);
}
$q = $this->db->get_where($this->tablename($table),$where);
$result = $q->result_array();
if($single) {
return $result[0];
}
return $result;
}
public function update($table, $where = array(), $data) {
$this->db->update($this->tablename($table),$data,$where);
return $this->db->affected_rows();
}
public function insert($table, $data) {
$this->db->insert($this->tablename($table),$data);
return $this->db->insert_id();
}
public function delete($table, $where = array()) {
$this->db->delete($this->tablename($table),$where);
return $this->db->affected_rows();
}
public function explicit($query) {
$q = $this->db->query($query);
if(is_object($q)) {
return $q->result_array();
} else {
return $q;
}
}
public function num_rows($table, $where = NULL) {
if(isset($where)){
$this->db->where($where);
}
$q = $this->db->get($table);
return $q->num_rows();
}
public function get_bot_data_by_hw_id($bot_hw_id) {
$q = $this->get('bots', array('bot_hw_id' => $bot_hw_id), TRUE);
return $q;
}
}
?>;
How can i fix this error?

Answer 1

First, I should mention that it's not absolutely a good and safe idea to query user input exactly without any process (as we see in your code). It's better to have different models at least for each table.
Anyway...
This way your function will be corrected:
public function get($table, $where = array(), $single = FALSE, $order = NULL) {
$this->db->where($where);
if(isset($order)) {
$this->db->order_by($order);
}
$q = $this->db->get_where($this->tablename($table),$where);
$result = $q->result_array();
// You should use $q->num_rows() to detect the number of returned rows
if($q->num_rows() == 1) {
// Return the first row:
return $result[0];
}
return $result;
}
It returns the first row when there is only one, and brings an array when $q->num_rows() is not equal to 1.
Hope it helps