how to return query in codeigniter code example

Example 1: codeigniter get num_rows

// num rows example
$this->db->select('*');
$this->db->where('whatever');
$query = $this->db->get('table');
$num = $query->num_rows();

Example 2: codeigniter raw query

$sql="Select * from my_table where 1";    
    $query = $this->db->query($SQL);
    return $query->result_array();

Example 3: get results from db and put in javascript array codeigniter

$query = $this->db->query("YOUR QUERY");

foreach ($query->result_array() as $row)
{
        echo $row['title'];
        echo $row['name'];
        echo $row['body'];
}

Example 4: raw query in codeigniter

$query = $db->query('YOUR QUERY HERE');